Justice White
announced the judgment of the Court and delivered the opinion of the Court as to Part II and an opinion as to Parts I, III, and IV, in which Justice Brennan, Justice Marshall, and Justice Blackmun join.
In this case, we review a judgment from a three-judge District Court, which sustained an equal protection challenge to Indiana's 1981 state apportionment on the basis that the law unconstitutionally diluted the votes of Indiana Democrats. 603 F. Supp. 1479 (SD Ind. 1984). Although we find such political gerrymandering to be justiciable, we conclude that the District Court applied an insufficiently demanding standard in finding unconstitutional vote dilution. Consequently, we reverse.
I
The Indiana Legislature, also known as the "General Assembly," consists of a House of Representatives and a Senate. There are 100 members of the House of Representatives, and 50 members of the Senate. The members of the House serve 2-year terms, with elections held for all seats every two years. The members of the Senate serve 4-year terms, and Senate elections are staggered so that half of the seats are up for election every two years. The members of both Houses are elected from legislative districts; but, while all Senate members are elected from single-member districts, House members are elected from a mixture of single-member and multimember districts. The division of the State into districts is accomplished by legislative enactment, which is signed by the Governor into law. Reapportionment is required every 10 years and is based on the federal decennial census. There is no prohibition against more frequent reapportionments.
In early 1981, the General Assembly initiated the process of reapportioning the State's legislative districts pursuant to the 1980 census. At this time, there were Republican majorities in both the House and the Senate, and the Governor was Republican. Bills were introduced in both Houses, and a reapportionment plan was duly passed and approved by the Governor. This plan provided 50 single-member districts for the Senate; for the House, it provided 7 triple-member, 9 double-member, and 61 single-member districts. In the Senate plan, the population deviation between districts was 1.15%; in the House plan, the deviation was 1.05%. The multimember districts generally included the more metropolitan areas of the State, although not every metropolitan area was in a multimember district. Marion County, which includes Indianapolis, was combined with portions of its neighboring counties to form five triple-member districts. Fort Wayne was divided into two parts, and each part was combined with portions of the surrounding county or counties to make two triple-member districts. On the other hand, South Bend was divided and put partly into a double-member district and partly into a single-member district (each part combined with part of the surrounding county or counties). Although county and city lines were not consistently followed, township lines generally were. The two plans, the Senate and the House, were not nested; that is, each Senate district was not divided exactly into two House districts. There appears to have been little relation between the lines drawn in the two plans.
In early 1982, this suit was filed by several Indiana Democrats (here the appellees) against various state officials (here the appellants), alleging that the 1981 reapportionment plans constituted a political gerrymander intended to disadvantage Democrats. Specifically, they contended that the particular district lines that were drawn and the mix of single-member and multimember districts were intended to and did violate their right, as Democrats, to equal protection under the Fourteenth Amendment. A three-judge District Court was convened to hear these claims.
In November 1982, before the case went to trial, elections were held under the new districting plan. All of the House seats and half of the Senate seats were up for election. Over all the House races statewide, Democratic candidates received 51.9% of the vote. Only 43 Democrats, however, were elected to the House. Over all the Senate races statewide, Democratic candidates received 53.1% of the vote. Thirteen (of twenty-five) Democrats were elected. In Marion and Allen Counties, both divided into multimember House districts, Democratic candidates drew 46.6% of the vote, but only 3 of the 21 House seats were filled by Democrats.
On December 13, 1984, a divided District Court issued a decision declaring the reapportionment to be unconstitutional, enjoining the appellants from holding elections pursuant to the 1981 redistricting, ordering the General Assembly to prepare a new plan, and retaining jurisdiction over the case. See 603 F. Supp. 1479.
To the District Court majority, the results of the 1982 elections seemed "to support an argument that there is a built-in bias favoring the majority party, the Republicans, which instituted the reapportionment plan." Id., at 1486. Although the court thought that these figures were unreliable predictors of future elections, it concluded that they warranted further examination of the circumstances surrounding the passage of the reapportionment statute. See ibid. In the course of this further examination, the court noted the irregular shape of some district lines, the peculiar mix of single-member and multimember districts, and the failure of the district lines to adhere consistently to political subdivision boundaries to define communities of interest. The court also found inadequate the other explanations given for the configuration of the districts, such as adherence to the one person, one vote imperative and the Voting Rights Act's no retrogression requirement. These factors, concluded the court, evidenced an intentional effort to favor Republican incumbents and candidates and to disadvantage Democratic voters. This was achieved by "stacking" Democrats into districts with large Democratic majorities and "splitting" them in other districts so as to give Republicans safe but not excessive majorities in those districts. Because the 1982 elections indicated that the plan also had a discriminatory-effect in that the proportionate voting influence of Democratic voters had been adversely affected and because any scheme "which purposely inhibit[s] or prevents] proportional representation cannot be tolerated," id., at 1492, the District Court invalidated the statute.
The defendants appealed, seeking review of the District Court's rulings that the case was justiciable and that, if justiciable, an equal protection violation had occurred. We noted probable jurisdiction. 470 U. S. 1083 (1985).
I — I H-H
We address first the question whether this case presents a justiciable controversy or a nonjusticiable political question. Although the District Court never explicitly stated that the case was justiciable, its holding clearly rests on such a finding. The appellees urge that this Court has in the past acknowledged and acted upon the justiciability of purely political gerrymandering claims. The appellants contend that we have affirmed on the merits decisions of lower courts finding such claims to be nonjusticiable.
A
Since Baker v. Carr, 369 U. S. 186 (1962), we have consistently adjudicated equal protection claims in the legislative districting context regarding inequalities in population between districts. In the course of these cases, we have developed and enforced the "one person, one vote" principle. See, e. g., Reynolds v. Sims, 377 U. S. 533 (1964).
Our past decisions also make clear that even where there is no population deviation among the districts, racial gerrymandering presents a justiciable equal protection claim. In the multimember district context, we have reviewed, and on occasion rejected, districting plans that unconstitutionally diminished the effectiveness of the votes of racial minorities. See Rogers v. Lodge, 458 U. S. 613 (1982); Mobile v. Bolden, 446 U. S. 55 (1980); White v. Regester, 412 U. S. 755 (1973); Whitcomb v. Chavis, 403 U. S. 124 (1971); Burns v. Richardson, 384 U. S. 73 (1966); Fortson v. Dorsey, 379 U. S. 433 (1965). We have also adjudicated claims that the configuration of single-member districts violated equal protection with respect to racial and ethnic minorities, although we have never struck down an apportionment plan because of such a claim. See United Jewish Organizations of Williamsburgh, Inc. v. Carey, 430 U. S. 144 (1977); Wright v. Rockefeller, 376 U. S. 52 (1964).
In the multimember district cases, we have also repeatedly stated that districting that would "operate to minimize or cancel out the voting strength of racial or political elements of the voting population" would raise a constitutional question. Fortson, supra, at 439 (emphasis added). See also Gaffney v. Cummings, 412 U. S. 735, 751 (1973); Whitcomb v. Chavis, supra, at 143; Burns v. Richardson, supra, at 88. Finally, in Gaffney v. Cummings, supra, we upheld against an equal protection political gerrymandering challenge a state legislative single-member redistricting scheme that was formulated in a bipartisan effort to try to provide political representation on a level approximately proportional to the strength of political parties in the State. In that case, we adjudicated the type of purely political equal protection claim that is brought here, although we did not, as a threshold matter, expressly hold such a claim to be justi-ciable. Regardless of this lack of a specific holding, our consideration of the merits of the claim in Gaffney in the face of a discussion of justiciability in appellant's brief, combined with our repeated reference in other opinions to the constitutional deficiencies of plans that dilute the vote of political groups, at the least supports an inference that these cases are justiciable.
In the years since Baker v. Carr, both before and after Gaffney, however, we have also affirmed a number of decisions in which the lower courts rejected the justiciability of purely political gerrymandering claims. In WMCA, Inc. v. Lomenzo, 382 U. S. 4 (1965), summarily aff'g 238 F. Supp. 916 (SDNY), the most frequently cited of these cases, we affirmed the decision of a three-judge District Court upholding a temporary apportionment plan for the State of New York. The District Court had determined that political gerrymandering equal protection challenges to this plan were nonjusticiable. See id., at 925-926. Justice Harlan, in his opinion concurring in the Court's summary affirmance, expressed his understanding that the affirmance was based on the Court's approval of the lower court's finding of non-justiciability. See 382 U. S., at 6. See also Jimenez v. Hidalgo County Water Improvement District No. 2, 424 U. S. 950 (1976), summarily aff'g 68 F. R. D. 668 (SD Tex. 1975); Ferrell v. Hall, 406 U. S. 939 (1972), summarily aff'g 339 F. Supp. 73 (WD Okla.); Wells v. Rockefeller, 398 U. S. 901 (1970), summarily aff'g 311 F. Supp. 48 (SDNY). Although these summary affirmances arguably support an inference that these claims are not justiciable, there are other cases in which federal or state courts adjudicated political gerrymandering claims and we summarily affirmed or dismissed for want of a substantial federal question. See, e. g., Wiser v. Hughes, 459 U. S. 962 (1982), dismissing for want of a substantial federal question an appeal from In re Legislative Districting, 299 Md. 658, 475 A. 2d 428; Kelly v. Bumpers, 413 U. S. 901 (1973), summarily aff'g 340 F. Supp. 568 (ED Ark. 1972); Archer v. Smith, 409 U. S. 808 (1972), summarily aff'g Graves v. Barnes, 343 F. Supp. 704, 734 (WD Tex.).
These sets of cases may look in different directions, but to the extent that our summary affirmances indicate the non-justiciability of political gerrymander cases, we are not bound by those decisions. As we have observed before, "[i]t is not at all unusual for the Court to find it appropriate to give full consideration to a question that has been the subject of previous summary action." Washington v. Yakima Indian Nation, 439 U. S. 463, 477, n. 20 (1979). See also Edelman v. Jordan, 415 U. S. 651, 670-671 (1974). The issue that the appellants would have us find to be precluded by these summary dispositions is an important one, and it deserves further consideration.
B
The outlines of the political question doctrine were described and to a large extent defined in Baker v. Carr. The synthesis of that effort is found in the following passage in the Court's opinion:
"It is apparent that several formulations which vary slightly according to the settings in which the questions arise may describe a political question, although each has one or more elements which identify it as essentially a function of the separation of powers. Prominent on the surface of any case held to involve a political question is found a textually demonstrable constitutional commitment of the issue to a coordinate political department; or a lack of judicially discoverable and manageable standards for resolving it; or the impossibility of deciding without an initial policy determination of a kind clearly for nonjudicial discretion; or the impossibility of a court's undertaking independent resolution without expressing lack of the respect due coordinate branches of government; or an unusual need for unquestioning adherence to a political decision already made; or the potentiality of embarrassment from multifarious pronouncements by various departments on one question.
"Unless one of these formulations is inextricable from the case at bar, there should be no dismissal for nonjusticiability on the ground of a political question's presence. The doctrine of which we treat is one of 'political questions,' not one of 'political cases.' The courts cannot reject as 'no law suit' a bona fide controversy as to whether some action denominated 'political' exceeds constitutional authority. The cases we have reviewed show the necessity for discriminating inquiry into the precise facts and posture of the particular case, and the impossibility of resolution by any semantic cataloguing." 369 U. S., at 217.
In Baker, the Court applied this analysis to an equal protection claim based on a state legislative apportionment that allowed substantial disparities in the number of voters represented by each state representative. See id., at 253-258 (Clark, J., concurring). In holding that claim to be justi-ciable, the Court concluded that none of the identifying characteristics of a political question were present:
"The question here is the consistency of state action with the Federal Constitution. We have no question decided, or to be decided, by a political branch of government coequal with this Court. Nor do we risk embarrassment of our government abroad, or grave disturbance at home if we take issue with Tennessee as to the constitutionality of her action here challenged. Nor need the appellants, in order to succeed in this action, ask the Court to enter upon policy determinations for which judicially manageable standards are lacking. Judicial standards under the Equal Protection Clause are well developed and familiar, and it has been open to courts since the enactment of the Fourteenth Amendment to determine, if on the particular facts they must, that a discrimination reflects no policy, but simply arbitrary and capricious action." Id., at 226.
This analysis applies equally to the question now before us. Disposition of this question does not involve us in a matter more properly decided by a coequal branch of our Government. There is no risk of foreign or domestic disturbance, and in light of our cases since Baker we are not persuaded that there are no judicially discernible and manageable standards by which political gerrymander cases are to be decided.
It is true that the type of claim that was presented in Baker v. Carr was subsequently resolved in this Court by the formulation of the "one person, one vote" rule. See, e. g., Reynolds v. Sims, 377 U. S., at 557-561. The mere fact, however, that we may not now similarly perceive a likely arithmetic presumption in the instant context does not compel a conclusion that the claims presented here are non-justiciable. The one person, one vote principle had not yet been developed when Baker was decided. At that time, the Court did not rely on the potential for such a rule in finding justiciability. Instead, as the language quoted above clearly indicates, the Court contemplated simply that legislative line drawing in the districting context would be susceptible of adjudication under the applicable constitutional criteria.
Furthermore, in formulating the one person, one vote formula, the Court characterized the question posed by election districts of disparate size as an issue of fair representation. In such cases, it is not that anyone is deprived of a vote or that any person's vote is not counted. Rather, it is that one electoral district elects a single representative and another district of the same size elects two or more — the elector's vote in the former district having less weight in the sense that he may vote for and his district be represented by only one legislator, while his neighbor in the adjoining district votes for and is represented by two or more. Reynolds accordingly observed:
"Since the achieving of fair and effective representation for all citizens is concededly the basic aim of legislative apportionment, we conclude that the Equal Protection Clause guarantees the opportunity for equal participation by all voters in the election of State legislators. Diluting the weight of votes because of place of residence impairs basic constitutional rights under the Fourteenth Amendment just as much as invidious discriminations based upon factors such as race . . . 377 U. S., at 565-566.
Reynolds surely indicates the justiciability of claims going to the adequacy of representation in state legislatures.
The issue here is of course different from that adjudicated in Reynolds. It does not concern districts of unequal size. Not only does everyone have the right to vote and to have his vote counted, but each elector may vote for and be represented by the same number of lawmakers. Rather, the claim is that each political group in a State should have the same chance to elect representatives of its choice as any other political group. Nevertheless, the issue is one of representation, and we decline to hold that such claims are never justiciable.
Our racial gerrymander cases such as White v. Regester and Whitcomb v. Chavis indicate as much. In those cases, there was no population variation among the districts, and no one was precluded from voting. The claim instead was that an identifiable racial or ethnic group had an insufficient chance to elect a representative of its choice and that district lines should be redrawn to remedy this alleged defect. In both cases, we adjudicated the merits of such claims, rejecting the claim in Whitcomb and sustaining it in Regester. Just as clearly, in Gaffney v. Cummings, where the districts also passed muster under the Reynolds formula, the claim was that the legislature had manipulated district lines to afford political groups in various districts an enhanced opportunity to elect legislators of their choice. Although advising caution, we said that "we must . . . respond to [the] claims . . . that even if acceptable populationwise, the . . . plan was invidiously discriminatory because a 'political fairness principle' was followed . . . 412 U. S., at 751-752 (emphasis added). We went on to hold that the statute at issue did not violate the Equal Protection Clause.
These decisions support a conclusion that this case is justi-ciable. As Gaffney demonstrates, that the claim is submitted by a political group, rather than a racial group, does not distinguish it in terms of justiciability. That the characteristics of the complaining group are not immutable or that the group has not been subject to the same historical stigma may be relevant to the manner in which the case is adjudicated, but these differences do not justify a refusal to entertain such a case.
In fact, Justice O'Connor's attempt to distinguish this political gerrymandering claim from the racial gerrymandering claims that we have consistently adjudicated demonstrates the futility of such an effort. Her conclusion that the claim in this case is not justiciable seems to rest on a dual concern that no judicially manageable standards exist and that adjudication of such claims requires an initial policy decision that the judiciary should not make. Yet she does not point out how the standards that we set forth here for adjudicating this political gerrymandering claim are less manageable than the standards that have been developed for racial gerrymandering claims. Nor does she demonstrate what initial policy decision — regarding, for example, the desirability of fair group representation — we have made here that we have not made in the race cases. She merely asserts that because race has historically been a suspect classification individual minority voters' rights are more immediately related to a racial minority group's voting strength. This, in combination with "the greater warrant the Equal Protection Clause gives the federal courts to intervene for protection against racial discrimination, suffice to render racial gerrymandering claims justiciable." Post, at 151 (O'Connor, J., concurring in judgment).
Reliance on these assertions to determine justiciability would transform the narrow categories of "political questions" that Baker v. Carr carefully defined into an ad hoc litmus test of this Court's reactions to the desirability of and need for judicial application of constitutional or statutory standards to a given type of claim. Justice O'Connor's own discussion seems to reflect such an approach: She concludes that because political gerrymandering may be a "self-limiting enterprise" there is no need for judicial intervention. Post, at 152. She also expresses concern that our decision today will lead to "political instability and judicial malaise," post, at 147, because nothing will prevent members of other identifiable groups from bringing similar claims. To begin with, Justice O'Connor's factual assumptions are by no means obviously correct: It is not clear that political gerrymandering is a self-limiting enterprise or that other groups will have any great incentive to bring gerrymandering claims, given the requirement of a showing of discriminatory intent. At a more fundamental level, however, Justice O'Connor's analysis is flawed because it focuses on the perceived need for judicial review and on the potential practical problems with allowing such review. Validation of the con sideration of such amorphous and wide-ranging factors in assessing justiciability would alter substantially the analysis the Court enunciated in Baker v. Carr, and we decline Justice O'Connor's implicit invitation to rethink that approach.
rH 1 ► — 1
Having determined that the political gerrymandering claim in this case is justiciable, we turn to the question whether the District Court erred in holding that the appellees had alleged and proved a violation of the Equal Protection Clause.
A
Preliminarily, we agree with the District Court that the claim made by the appellees in this case is a claim that the 1981 apportionment discriminates against Democrats on a statewide basis. Both the appellees and the District Court have cited instances of individual districting within the State which they believe exemplify this discrimination, but the ap-pellees' claim, as we understand it, is that Democratic voters over the State as a whole, not Democratic voters in particular districts, have been subjected to unconstitutional discrimination. See, e. g., Complaint of Bandemer Plaintiffs 3-7. Although the statewide discrimination asserted here was allegedly accomplished through the manipulation of individual district lines, the focus of the equal protection inquiry is necessarily somewhat different from that involved in the review of individual districts.
We also agree with the District Court that in order to succeed the Bandemer plaintiffs were required to prove both intentional discrimination against an identifiable political group and an actual discriminatory effect on that group. See, e. g., Mobile v. Bolden, 446 U. S., at 67-68. Further, we are confident that if the law challenged here had discriminatory effects on Democrats, this record would support a finding that the discrimination was intentional. Thus, we decline to overturn the District Court's finding of discriminatory intent as clearly erroneous.
Indeed, quite aside from the anecdotal evidence, the shape of the House and Senate Districts, and the alleged disregard for political boundaries, we think it most likely that whenever a legislature redistricts, those responsible for the legislation will know the likely political composition of the new districts and will have a prediction as to whether a particular district is a safe one for a Democratic or Republican candidate or is a competitive district that either candidate might win. As we said in Gaffney v. Cummings, 412 U. S., at 752-753:
"It would be idle, we think, to contend that any political consideration taken into account in fashioning a reapportionment plan is sufficient to invalidate it. Our cases indicate quite the contrary. See White v. Regester, [412 U. S. 755 (1973)]; Burns v. Richardson, [384 U. S. 73 (1966)]; Whitcomb v. Chavis, [403 U. S. 124 (1971)]; Abate v. Mundt, [403 U. S. 182 (1971)]. The very essence of districting is to produce a different— a more 'politically fair' — result than would be reached with elections at large, in which the winning party would take 100% of the legislative seats. Politics and political considerations are inseparable from districting and apportionment. The political profile of a State, its party registration, and voting records are available precinct by precinct, ward by ward. These subdivisions may not be identical with census tracts, but, when overlaid on a census map, it requires no special genius to recognize the political consequences of drawing a district line along one street rather than another. It is not only obvious, but absolutely unavoidable, that the location and shape of districts may well determine the political complexion of the area. District lines are rarely neutral phenomena. They can well determine what district will be predominantly Democratic or predominantly Republican, or make a close race likely. Redistricting may pit incumbents against one another or make very difficult the elec tion of the most experienced legislator. The reality is that districting inevitably has and is intended to have substantial political consequences.
"It may be suggested that those who redistrict and reapportion should work with census, not political, data and achieve population equality without regard for political impact. But this politically mindless approach may produce, whether intended or not, the most grossly gerrymandered results; and, in any event, it is most unlikely that the political impact of such a plan would remain undiscovered by the time it was proposed or adopted, in which event the results would be both known and, if not changed, intended."
As long as redistricting is done by a legislature, it should not be very difficult to prove that the likely political consequences of the reapportionment were intended.
B
We do not accept, however, the District Court's legal and factual bases for concluding that the 1981 Act visited a sufficiently adverse effect on the appellees' constitutionally protected rights to make out a violation of the Equal Protection Clause. The District Court held that because any apportion ment scheme that purposely prevents proportional representation is unconstitutional, Democratic voters need only show that their proportionate voting influence has been adversely affected. 603 F. Supp., at 1492. Our cases, however, clearly foreclose any claim that the Constitution requires proportional representation or that legislatures in reapportioning must draw district lines to come as near as possible to allocating seats to the contending parties in proportion to what their anticipated statewide vote will be. Whitcomb v. Chavis, 403 U. S., at 153, 156, 160; White v. Regester, 412 U. S., at 765-766.
The typical election for legislative seats in the United States is conducted in described geographical districts, with the candidate receiving the most votes in each district winning the seat allocated to that district. If all or most of the districts are competitive — defined by the District Court in this case as districts in which the anticipated split in the party vote is within the range of 45% to 55% — even a narrow statewide preference for either party would produce an overwhelming majority for the winning party in the state legislature. This consequence, however, is inherent in winner-take-all, district-based elections, and we cannot hold that such a reapportionment law would violate the Equal Protection Clause because the voters in the losing party do not have representation in the legislature in proportion to the statewide vote received by their party candidates. As we have said: "[W]e are unprepared to hold that district-based elections decided by plurality vote are unconstitutional in either single- or multi-member districts simply because the supporters of losing candidates have no legislative seats assigned to them." Whitcomb v. Chavis, supra, at 160. This is true of a racial as well as a political group. White v. Regester, supra, at 765-766. It is also true of a statewide claim as well as an individual district claim.
To draw district lines to maximize the representation of each major party would require creating as many safe seats for each party as the demographic and predicted political characteristics of the State would permit. This in turn would leave the minority in each safe district without a representative of its choice. We upheld this "political fairness" approach in Gaffney v. Cummings, despite its tendency to deny safe district minorities any realistic chance to elect their own representatives. But Gaffney in no way suggested that the Constitution requires the approach that Connecticut had adopted in that case.
In cases involving individual multimember districts, we have required a substantially greater showing of adverse effects than a mere lack of proportional representation to support a finding of unconstitutional vote dilution. Only where there is evidence that excluded groups have "less opportunity to participate in the political processes and to elect candidates of their choice" have we refused to approve the use of multimember districts. Rogers v. Lodge, 458 U. S., at 624. See also United Jewish Organizations of Williamsburgh, Inc. v. Carey, 430 U. S., at 167; White v. Regester, supra, at 765-766; Whitcomb v. Chavis, supra, at 150. In these cases, we have also noted the lack of responsiveness by those elected to the concerns of the relevant groups. See Rogers v. Lodge, supra, at 625-627; White v. Regester, supra, at 766-767.
These holdings rest on a conviction that the mere fact that a particular apportionment scheme makes it more difficult for a particular group in a particular district to elect the representatives of its choice does not render that scheme constitutionally infirm. This conviction, in turn, stems from a per ception that the power to influence the political process is not limited to winning elections. An individual or a group of individuals who votes for a losing candidate is usually deemed to be adequately represented by the winning candidate and to have as much opportunity to influence that candidate as other voters in the district. We cannot presume in such a situation, without actual proof to the contrary, that the candidate elected will entirely ignore the interests of those voters. This is true even in a safe district where the losing group loses election after election. Thus, a group's electoral power is not unconstitutionally diminished by the simple fact of an apportionment scheme that makes winning elections more difficult, and a failure of proportional representation alone does not constitute impermissible discrimination under the Equal Protection Clause. See Mobile v. Bolden, 446 U. S., at 111, n. 7 (Marshall, J., dissenting).
As with individual districts, where unconstitutional vote dilution is alleged in the form of statewide political gerrymandering, the mere lack of proportional representation will not be sufficient to prove unconstitutional discrimination. Again, without specific supporting evidence, a court cannot presume in such a case that those who are elected will disregard the disproportionately underrepresented group. Rather, unconstitutional discrimination occurs only when the electoral system is arranged in a manner that will consistently degrade a voter's or a group of voters' influence on the political process as a whole.
Although this is a somewhat different formulation than we have previously used in describing unconstitutional vote dilution in an individual district, the focus of both of these inquiries is essentially the same. In both contexts, the question is whether a particular group has been unconstitutionally de nied its chance to effectively influence the political process. In a challenge to an individual district, this inquiry focuses on the opportunity of members of the group to participate in party deliberations in the slating and nomination of candidates, their opportunity to register and vote, and hence their chance to directly influence the election returns and to secure the attention of the winning candidate. Statewide, however, the inquiry centers on the voters' direct or indirect influence on the elections of the state legislature as a whole. And, as in individual district cases, an equal protection violation may be found only where the electoral system substan-tjally~disadyantages certain voters in tiheir,opportunity to influence,.rthe.-p0liticar pr5cés's' effectively. In this context^ such a finding of unconstitutiohality 'must be supported by evidence of continued frustration of the will of a majority of the voters or effective denial to a minority of voters of a fair chance to influence the political process.
Based on these views, we would reject the District Court's apparent holding that any interference with an opportunity to elect a representative of one's choice would be sufficient to allege or make out an equal protection violation, unless justified by some acceptable state interest that the State would be required to demonstrate. In addition to being contrary to the above-described conception of an unconstitutional political gerrymander, such a low threshold for legal action would invite attack on all or almost all reapportionment statutes. District-based elections hardly ever produce a perfect fit between votes and representation. The one person, one vote imperative often mandates departure from this result as does the no-retrogression rule required by § 5 of the Voting Rights Act. Inviting attack on minor departures from some supposed norm would too much embroil the judiciary in second-guessing what has consistently been referred to as a political task for the legislature, a task that should not be monitored too closely unless the express or tacit goal is to effect its removal from legislative halls. We decline to take a major step toward that end, which would be so much at odds with our history and experience.
The view that a prima facie case of illegal discrimination in reapportionment requires a showing of more than a de minimis effect is not unprecedented. Reapportionment cases involving the one person, one vote principle such as Gaffney v. Cummings and White v. Regester provide support for such a requirement. In the present, considerably more complex context, it is also appropriate to require allegations and proof that the challenged legislative plan has had or will have effects that are sufficiently serious to require intervention by the federal courts in state re apportionment decisions.
C
The District Court's findings do not satisfy this threshold condition to stating and proving a cause of action. In reaching its conclusion, the District Court relied primarily on the results of the 1982 elections: Democratic candidates for the State House of Representatives had received 51.9% of the votes cast statewide and Republican candidates 48.1%; yet, out of the 100 seats to be filled, Republican candidates won 57 and Democrats 43. In the Senate, 53.1% of the votes were cast for Democratic candidates and 46.9% for Republicans; of the 25 Senate seats to be filled, Republicans won 12 and Democrats 13. The court- also relied upon the use of multi-member districts in Marion and Allen Counties, where Democrats or those inclined to vote Democratic in 1982 amounted to 46.6% of the population of those counties but Republicans won 86% — 18 of 21 — seats allocated to the districts in those counties. These disparities were enough to require a neutral justification by the State, which in the eyes of the District Court was not forthcoming.
Relying on a single election to prove unconstitutional discrimination is unsatisfactory. The District Court observed, and the parties do not disagree, that Indiana is a swing State. Voters sometimes prefer Democratic candidates, and sometimes Republican. The District Court did not find that because of the 1981 Act the Democrats could not in one of the next few elections secure a sufficient vote to take control of the assembly. Indeed, the District Court declined to hold that the 1982 election results were the predictable consequences of the 1981 Act and expressly refused to hold that those results were a reliable prediction of future ones. The District Court did not ask by what percentage the statewide Democratic vote would have had to increase to control either the House or the Senate. The appellants argue here, without a persuasive response from the appellees, that had the Democratic candidates received an additional few percentage points of the votes cast statewide, they would have obtained a majority of the seats in both houses. Nor was there any finding that the 1981 reapportionment would consign the Democrats to a minority status in the Assembly throughout the 1980's or that the Democrats would have no hope of doing any better in the reapportionment that would occur after the 1990 census. Without findings of this nature, the District Court erred in concluding that the 1981 Act violated the Equal Protection Clause.
The District Court's discussion of the multimember districts created by the 1981 Act does not undermine this conclusion. For the purposes of the statewide political gerrymandering claim, these districts appear indistinguishable from safe Republican and safe Democratic single-member districts. Simply showing that there are multimember districts in the State and that those districts are constructed so as to be safely Republican or Democratic in no way bolsters the contention that there has been statewide discrimination against Democratic voters. It could be, were the necessary threshold effect to be shown, that multimember districts could be demonstrated to be suspect on the ground that they are particularly useful in attaining impermissibly discriminatory ends; at this stage of the inquiry, however, the multimember district evidence does not materially aid the appellees' case.
Furthermore, in determining the constitutionality of multi-member districts challenged as racial gerrymanders, we have rejected the view that "any group with distinctive interests must be represented in legislative halls if it is numerous enough to command at least one seat and represents a minority living in an area sufficiently compact to constitute a single-member district." Whitcomb, 403 U. S., at 156. Rather, we have required that there be proof that the complaining minority "had less opportunity . to participate in the political processes and to elect legislators of their choice." Id., at 149. In Whitcomb, we went on to observe that there was no proof that blacks were not allowed to register or vote, to choose the political party they desired to support, to participate in its affairs or to be equally represented on those occasions when candidates were chosen, or to be included among the candidates slated by the Democratic Party. Against this background, we concluded that the failure of the minority "to have legislative seats in proportion to its population emerges more as a function of losing elections than of built-in bias against poor Negroes. The voting power of ghetto residents may have been 'cancelled out' as the District Court held, but this seems a mere euphemism for political defeat at the polls." Id., at 153. Whitcomb accordingly rejected a challenge to multimember districts in Marion County, Indiana. A similar challenge was sustained in White v. Regester, but only by employing the same criterion, namely, that the plaintiffs must produce evidence to support a finding "that the political processes leading to nomination and election were not equally open to participation by the group in question — that its members had less opportunity than did other residents in the district to participate in the political processes and to elect legislators of their choice." 412 U. S., at 766.
This participatory approach to the legality of individual multimember districts is not helpful where the claim is that such districts discriminate against Democrats, for it could hardly be said that Democrats, any more than Republicans, are excluded from participating in the affairs of their own party or from the processes by which candidates are nominated and elected. For constitutional purposes, the Democratic claim in this case, insofar as it challenges vel non the legality of the multimember districts in certain counties, is like that of the Negroes in Whitcomb who failed to prove a racial gerrymander, for it boils down to a complaint that they failed to attract a majority of the voters in the challenged multimember districts.
D
In response to our approach, Justice Powell suggests an alternative method for evaluating equal protection claims of political gerrymandering. In his view, courts should look at a number of factors in considering these claims: the nature of the legislative procedures by which the challenged redistricting was accomplished and the intent behind the redistricting; the shapes of the districts and their conformity with political subdivision boundaries; and "evidence concerning population disparities and statistics tending to show vote dilution." Post, at 173 (concurring in part and dissenting in part). The District Court in this case reviewed these factors in reaching its ultimate conclusion that unconstitutional vote dilution had occurred, and Justice Powell concludes that its findings on these factors — and on the ultimate question of vote discrimination — should be upheld. According to Justice Powell, those findings adequately support a conclusion that "the boundaries of the voting districts have been distorted deliberately and arbitrarily to achieve illegitimate ends." Post, at 165. This deliberate and arbitrary distortion of boundaries, in turn, apparently distinguishes gerrymandering in a "loose" sense, "the common practice of the party in power to choose the redistricting plan that gives it an advantage at the polls," post, at 164, from gerrymandering in an "unconstitutional" sense.
Although we are not completely clear as to the distinction between these two categories of gerrymander, the crux of Justice Powell's analysis seems to be that — at least in some cases — the intentional drawing of district boundaries for partisan ends and for no other reason violates the Equal Protection Clause in and of itself. We disagree, however, with this conception of a constitutional violation. Specifically, even if a state legislature redistricts with the specific intention of disadvantaging one political party's election prospects, we do not believe that there has been an unconstitutional discrimination against members of that party unless the redistricting does in fact disadvantage it at the polls.
Moreover, as we discussed above, a mere lack of proportionate results in one election cannot suffice in this regard. We have reached this conclusion in our cases involving challenges to individual multimember districts, and it applies equally here. In the individual multimember district cases, we have found equal protection violations only where a history of disproportionate results appeared in conjunction with strong indicia of lack of political power and the denial of fair representation. See supra, at 131. In those cases, the racial minorities asserting the successful equal protection claims had essentially been shut out of the political process. In the statewide political gerrymandering context, these prior cases lead to the analogous conclusion that equal protection violations may be found only where a history (actual or projected) of disproportionate results appears in conjunction with similar indicia. The mere lack of control of the General Assembly after a single election does not rise to the requisite level.
This requirement of more than a showing of possibly transitory results is where we appear to depart from Justice Powell. Stripped of its "factors" verbiage, Justice Powell's analysis turns on a determination that a lack of proportionate election results can support a finding of an equal protection violation, at least in some circumstances. Here, the only concrete effect on the Democrats in Indiana in terms of election results that the District Court had before it was one election in which the percentage of Democrats elected was lower than the percentage of total Democratic votes cast. In Justice Powell's view, this disproportionality, when combined with clearly discriminatory intent on the part of the 1981 General Assembly and the manipulation of district lines in the apportionment process, is sufficient to conclude that fair representation has been denied.
The factors other than disproportionate election results, however, do not contribute to a finding that Democratic voters have been disadvantaged in fact. They support a finding that an intention to discriminate was present and that districts were drawn in accordance with that intention, but they do not show any actual disadvantage beyond that shown by the election results: It surely cannot be an actual disadvantage in terms of fair representation on a group level just to be placed in a district with a supermajority of other Demo- eratic voters or a district that departs from pre-existing political boundaries. Only when such placement affects election results and political power statewide has an actual disadvantage occurred.
Consequently, Justice Powell's view would allow a constitutional violation to be found where the only proven effect on a political party's electoral power was disproportionate results in one (or possibly two) elections. This view, however, contains no explanation of why a lack of proportionate election results should suffice in these political gerrymandering cases while it does not in the cases involving racial gerrymandering. In fact, Justice Powell's opinion is silent as to the relevance of the substantive standard developed in the multimember district cases to these political gerrymandering cases.
In rejecting Justice Powell's approach, we do not mean to intimate that the factors he considers are entirely irrelevant. The election results obviously are relevant to a showing of the effects required to prove a political gerrymandering claim under our view. And the district configurations may be combined with vote projections to predict future election results, which are also relevant to the effects showing. The other factors, even if not relevant to the effects issue, might well be relevant to an equal protection claim. The equal protection argument would proceed along the following lines: If there were a discriminatory effect and a discriminatory intent, then the legislation would be examined for valid underpinnings. Thus, evidence of exclusive legislative process and deliberate drawing of district lines in accordance with accepted gerrymandering principles would be relevant to intent, and evidence of valid and invalid configuration would be relevant to whether the districting plan met legitimate state interests.
This course is consistent with our equal protection cases generally and is the course we follow here: We assumed that there was discriminatory intent, found that there was insuffi cient discriminatory effect to constitute an equal protection violation, and therefore did not reach the question of the state interests (legitimate or otherwise) served by the particular districts as they were created by the legislature. Consequently, the valid or invalid configuration of the districts was an issue we did not need to consider.
It seems inappropriate, however, to view these separate components of an equal protection analysis as "factors" to be considered together without regard for their separate functions or meaning. This undifferentiated consideration of the various factors confuses the import of each factor and disguises the essential conclusion of Justice Powell's opinion: that disproportionate election results alone are a sufficient effect to support a finding of a constitutional violation.
In sum, we decline to adopt the approach enunciated by Justice Powell. In our view, that approach departs from our past cases and invites judicial interference in legislative districting whenever a political party suffers at the polls. We recognize that our own view may be difficult of application. Determining when an electoral system has been "ar ranged in a manner that will consistently degrade a voter's or a group of voters' influence on the political process as a whole," supra, at 132, is of necessity a difficult inquiry. Nevertheless, we believe that it recognizes the delicacy of intruding on this most political of legislative functions and is at the same time consistent with our prior cases regarding individual multimember districts, which have formulated a parallel standard.
IV
In sum, we hold that political gerrymandering cases are properly justiciable under the Equal Protection Clause. We also conclude, however, that a threshold showing of discriminatory vote dilution is required for a prima facie case of an equal protection violation. In this case, the findings made by the District Court of an adverse effect on the appellees do not surmount the threshold requirement. Consequently, the judgment of the District Court is
Reversed.
Politically speaking, the State of Indiana is a "swing" State: It has supported both the Democrats and the Republicans at various times, often following national trends and major candidates. Although at times within the last few decades the State has voted up to 56% Democratic, in 1980 the Republicans took the State.
These bills were "vehicle bills" — bills that had no real content. Both bills were passed and were then referred to the other House and eventually to a Conference Committee, which consisted entirely of Republican members. Four Democratic "advisers" to the Committee were appointed, but they had no voting powers. Further, they were excluded from the substantive work of the Committee: The Republican State Committee funded a computerized study by an outside firm that produced the districting map that was eventually used, and the Democratic "advisers" were not allowed access to the computer or to the results of the study. They nevertheless attempted to develop apportionment proposals of their own using the 1980 census data. A few days before the end of the 1981 legislative session, the Conference Committee presented its plan to the legislature. The Democratic minority also presented its alternative plan. The majority plan was passed in both Houses with voting along party lines and was signed into law by the Governor.
A multitude of conflicting statistical evidence was also introduced at the trial. The District Court, however, specifically declined to credit any of this evidence, noting that it did not "wish to choose which statistician is more credible or less credible." 603 F. Supp., at 1485.
The court noted that various House districts combined urban and suburban or rural voters with dissimilar interests and that many of the districts were unwieldy shapes. Using Marion County as one example, the court observed that the county itself had exactly the population to support 14 House seats; nevertheless, it was combined with various surrounding areas to form five triple-member districts, which maintained the county's prior 15-member delegation even though it had in fact suffered a population decrease. Believing that the resulting multimember districts were suspect in terms of compactness, the court concluded that no rational reason could support them.
In addition, the court quoted from the deposition testimony of the Speaker of the House as follows:
"MR. SUSSMAN: What I would like you to do here again is to give me whatever reasons were operative to your mind in maintaining or creating multi-member districts with regard to (Districts) 48 through 52 [the Marion County districts].
"MR. DAILEY: Political.
"MR. SUSSMAN: What were the political factors?
"MR. DAILEY: We wanted to save as many incumbent Republicans as possible." Id., at 1484.
The court also quoted from the deposition testimony of Senator Bosma as follows:
"MR. SUSSMAN: This (newspaper) article says further, 'Under further questioning from Townsend about input in actual map drawing, Bosma said "You will have the privilege to offer a minority map. But I will advise you in advance that it will not be accepted." ' Is that accurate?
"MR. BOSMA: That's accurate. I might add that I don't make goals for the opposite team." Ibid.
These are familiar techniques of political gerrymandering. Democratic (or Republican, as the case may be) votes are "stacked" and "wasted" by creating districts where Democrats form majorities much greater than the 50% necessary to carry those districts. Concurrently, Republican votes are spread among districts in which they form safe, perhaps 55%, majorities, and Democratic votes are "cracked" or "split" by dispersing them in such a way as to be ineffectual.
Judge Pell, writing in dissent, disagreed. Assuming for the purposes of his analysis that a political gerrymandering case was justiciable, he concluded that the appellees had not proved discrimination. Rather, once the relative voting strengths were properly ascertained, it was his view that the plan had advantaged and disadvantaged both parties equally: The Democrats won more than their voting strength in the Senate and less in the House. See id., at 1501-1502. Judge Pell also rejected the majority's analysis of the multimember districts and thought that the State had followed rational nondiscriminatory criteria in formulating the 1981 plan.
Consolidated with this suit in the proceedings below was another lawsuit, filed by the Indiana NAACP. The NAACP suit challenged the plans as unconstitutional dilutions of the black vote in Indiana in violation of the Fourteenth and Fifteenth Amendments and the Voting Rights Act of 1965, 42 U. S. C. § 1973 (as amended).
In rejecting the NAACP claims, the District Court majority found: "[T]he voting efficacy of the NAACP plaintiffs was impinged upon because of their politics and not because of their race. It is not in dispute that blacks in this state vote overwhelmingly Democratic." 603 F. Supp., at 1489-1490. Consequently, the majority found no Fifteenth Amendment or Voting Rights Act violation. The dissent concurred with this result but gave different reasons for reaching this conclusion.
The NAACP did not appeal these dispositions. Consequently, the only claims now before us are the political gerrymandering claims.
As to the illegitimate policy determinations that Justice O'CONNOR believes that we have made, she points to two. The first is a preference for nonpartisan as opposed to partisan gerrymanders, and the second is a preference for proportionality. On a group level, however, which must be our focus in this type of claim, neither of these policy determinations is "of a kind clearly for nonjudicial discretion." Baker v. Carr, 369 U. S. 186, 217 (1962). The first merely recognizes that nonpartisan gerrymanders in fact are aimed at guaranteeing rather than infringing fair group representation. The second, which is not a preference for proportionality per se but a preference for a level of parity between votes and representation sufficient to ensure that significant minority voices are heard and that majorities are not consigned to minority status, is hardly an illegitimate extrapolation from our general majoritarian ethic and the objective of fair and adequate representation recognized in Reynolds v. Sims, 377 U. S. 533 (1964).
This passage from Gaffney expresses a view similar to that of Robert G. Dixon, Jr., one of the foremost scholars of reapportionment, who observed:
"[W]hether or not nonpopulation factors are expressly taken into account in shaping political districts, they are inevitably everpresent and operative. They influence all election outcomes in all sets of districts. The key concept to grasp is that there are no neutral lines for legislative districts . . . every line drawn aligns partisans and interest blocs in a particular way different from the alignment that would result from putting the line in some other place." Dixon, Fair Criteria and Procedures for Establishing Legislative Districts 7-8, in Representation and Redistricting Issues (B. Grofman, A. Lijphart, R. McKay, & H. Searrow eds. 1982).
That discriminatory intent may not be difficult to prove in this context does not, of course, mean that it need not be proved at all to succeed on such a claim.
Although these cases involved racial groups, we believe that the principles developed in these cases would apply equally to claims by political groups in individual districts. We note, however, that the elements necessary to a successful vote dilution claim may be more difficult to prove in relation to a claim by a political group. For example, historical patterns of exclusion from the political processes, evidence which would support a vote dilution claim, are in general more likely to be present for a racial group than for a political group.
Although this opinion relies on our cases relating to challenges by racial groups to individual multimember districts, nothing herein is intended in any way to suggest an alteration of the standards developed in those cases for evaluating such claims.
The requirement of a threshold showing is derived from the peculiar characteristics of these political gerrymandering claims. We do not contemplate that a similar requirement would apply to our Equal Protection cases outside of this particular context.
The District Court apparently thought that the political group suffering discrimination was all those voters who voted for Democratic Assembly candidates in 1982. Judge Pell, in dissent, argued that the allegedly disfavored group should be defined as those voters who could be counted on to vote Democratic from election to election, thus excluding those who vote the Republican ticket from time to time. He would have counted the true believers by averaging the Democratic vote cast in two different elections for those statewide offices for which party-line voting is thought to be the rule and personality and issue-oriented factors are relatively unimportant. Although accepting Judge Pell's definition of Democratic voters would have strongly suggested that the 1981 reapportionment had no discriminatory effect at all, there was no response to his position. The appellees take up the challenge in this Court, claiming that Judge Pell chose the wrong election years for the purpose of averaging the Democratic votes. The dispute need not now be resolved.
It should be noted that even if the District Court correctly identified constitutional shortcomings in the House districting, this did not automatically call for invalidating the provisions for the Senate. The only relevant fact about the Senate appearing in the District Court's findings is that in the 1982 elections to fill 25 Senate seats, Democrats won 53.1% of the statewide vote and elected 13 of their candidates. That on its face is hardly grounds for invalidating the Senate districting, and we have coun-selled before against striking down an entire apportionment statute when the constitutional evil could be cured by lesser means. Whitcomb v. Chavis, 403 U. S., at 160-161.
Although Justice Powell asserts that we mischaracterize these cases and that any effects in addition to disproportionality were required to be demonstrated only to prove discriminatory intent, we note that the effects test we cite was initially set forth in White v. Regester, 412 U. S. 755 (1973), which was decided before the Court expressly determined that proof of discriminatory intent was a necessary component of an equal protection claim. Moreover, the Voting Rights Act, which to a large extent borrowed the effects test from White, explicitly declined to require any showing of discriminatory intent. It may be true that our more recent cases have turned on the question of discriminatory intent, but that does not imply that we have abandoned the effects discussion we adopted earlier. Moreover, we believe that Justice Powell incorrectly asserts that more than one election must pass before a successful racial or political gerrymandering claim may be brought. Post, at 171-172, n. 10 (concurring in part and dissenting in part). Projected election results based on district boundaries and past voting patterns may certainly support this type of claim, even where no election has yet been held under the challenged districting.
Justice Powell proffers additional election results from the 1984 elections in support of his conclusion. These results were not considered by the District Court, and we decline to determine their significance without the benefit of any factual development as to their meaning in terms of Democratic power overall or in the long run. Nevertheless, we note that in terms of actual percentages, the 1984 House election results cited by Justice Powell exhibited less of a discrepancy between Democratic votes east and Democratic representatives elected than did the 1982 results (5% as opposed to 8%). This casts at least some doubt on the import of the 1982 results.
In most equal protection cases, it is true, a discriminatory effect will be readily apparent, and no heightened effect will be required, see n. 14, supra, but that is the only real difference between this type of equal protection claim and others.
Thus, we have rejected none of the District Court's subsidiary factual conclusions. We have merely, based on our view of the applicable law, disregarded those that were irrelevant in this case and held insufficient those that inadequately supported the District Court's ultimate legal conclusions. Specifically, we have not rejected the District Court's finding of discriminatory intent. Nor have we rejected the District Court's findings as to any of the election results or the contours of particular districts. We have simply determined that aside from the election results, none of the facts found by the District Court were relevant to the question of discriminatory effects. Consequently, since we did not need to progress beyond that point, given our conclusion that no unconstitutional discriminatory effects were shown as a matter of law, we did not need to consider the District Court's factual findings on the other "factors" addressed by Justice Powell.
Although we recognize the difficulty of this inquiry, we do not share Justice O'Connoh's apparent lack of faith in the lower courts' abilities to distinguish between disproportionality per se and the lack of fair representation that continued disproportionality in conjunction with other indi-cia may demonstrate. See post, at 157 (opinion concurring in judgment).
We are puzzled by Justice Powell's conclusion that we contemplate a test under which only the "one person, one vote" requirement has any relevance. This opinion clearly does not adopt such a limited review.