Opinion for the Court filed by Circuit Judge SENTELLE.
Dissenting opinion filed by Circuit Judge WALD.
SENTELLE, Circuit Judge:
Appellants challenge the constitutionality of an ethics regulation allowing employees of the Environmental Protection Agency ("EPA") to accept reimbursement for travel expenses they incur in giving "official" speeches, but not "unofficial" speeches, as violative of their First Amendment rights. The District Court granted summary judgment against them on their facial challenge, but allowed the litigation to proceed as to their as-applied challenge under the First Amendment. 786 F.Supp. 1033. We, too, reject their facial challenge and therefore affirm. We do not pass on their selective enforcement claim, which remains pending before the District Court.
I.
Appellants William Sanjour and Hugh Kaufman have been employed by the EPA in Washington, D.C. since the 1970s. During that time, both have traveled across the country giving unofficial speeches criticizing the' policies of the EPA. In the past, they routinely accepted reimbursement from the organization sponsoring their speeches for their travel and related expenses. Under prior law, they were allowed to do so, as long as the sponsoring organization was not a "prohibited source" (i.e., did no business with, and was not regulated by, the EPA) and as long as they gave the speeches on their own time without implying that they presented anything other than their personal opinions. See Office of Gov't Ethics Memorandum No. 84 X 5 (May 1, 1984).
On January 17,1991, however, the Office of Government Ethics ("OGE") adopted a rule that interprets existing ethics law to preclude any federal employee from "receiving compensation, including travel expenses, for speaking or writing on subject matter that focuses specifically on his official duties or on the responsibilities, policies and programs of his employing agency." 56 Fed.Reg. 1,721, 1,724 (1991) (to be codified at 5 C.F.R. § 2636.202(b) (1992)). The EPA distributed this regulation to its employees with an Ethics Advisory expressing its understanding that the rule allows expense reimbursement for "official" but not "unofficial" speech. See EPA Ethics Advisory 91-1, at 3 & n. 5 (Apr. 2, 1991) (opining that "[e]mployees may not accept non-official travel expenses . [but] [w]ith the required prior approvals, employees may continue to accept travel reimbursement for official travel"). Though the Ethics Advisory does not define the terms "official" and "unofficial," the EPA has elsewhere provided that speech or writing is official "if it results from a request to EPA to furnish a speaker, author or editor . [or] is tendered because of the employee's EPA position rather than the employee's individual knowledge or accomplishments." 40 C.F.R. § 3.503 (1991).
Because the OGE/EPA regulation barred them from accepting travel-expense reimbursement for unofficial speech, Sanjour and Kaufman declined speaking invitations by organizations located outside the Washington, D.C. metropolitan area. Among the organizations both turned down was appellant North Carolina Waste Awareness and Reduction Network ("NC WARN"). NC WARN, a North Carolina environmental coalition, had invited them to speak about EPA policies in an unofficial capacity at a public hearing concerning a plan to build a commercial hazardous waste incinerator in Northampton County, N.C. When Sanjour and Kaufman declined its invitation, NC WARN cancelled the public hearing.
Appellants then filed this lawsuit against appellees, the EPA, the OGE, the EPA Administrator and the OGE Director, and others not before this Court, challenging the legality of the OGE/EPA regulation on both statutory and First Amendment grounds. The District Court granted appellees' motion for summary judgment on the statutory claims and on the facial challenge under the First Amendment. However, the District Court held that appellants' as-applied challenge involved disputed issues of material fact and denied summary judgment. Sanjour v. EPA, 786 F.Supp. 1033 (D.D.C.1992). The as-applied challenge therefore remains pending before the District Court.
Before this Court, appellants, with support from the State of Alabama and a host of environmental organizations from various localities as amicus curiae, renew their contention that the OGE/EPA regulation is overbroad and underinclusive and therefore, on its face, violates the First Amendment. We emphasize that the facial challenge is all that is before us today; appellants elected not to appeal the District Court's dismissal of their statutory claims, and their selective enforcement claim remains before the District Court. Our task in this case, then, is a narrow one—we must decide whether the OGE/EPA regulation, on its face, violates the First Amendment on the asserted grounds.
II.
The parties disagree on the level of scrutiny applicable to this case. Appellants claim that we must apply strict scrutiny, under which the government "must show that its regulation is necessary to serve a compelling state interest and is narrowly drawn to achieve that end." Simon & Schuster v. Members of the New York State Crime Victims Bd., — U.S. -, -, 112 S.Ct. 501, 509, 116 L.Ed.2d 476 (1991) (quoting Arkansas Writers' Project, Inc. v. Ragland, 481 U.S. 221, 231, 107 S.Ct. 1722, 1729, 95 L.Ed.2d 209 (1987)). By contrast, appellees argue that we must, in the Supreme Court's words, balance "the interests of the [public employee], as a citizen, in commenting upon matters of public concern and the interest of the State, as an employer, in promoting the efficiency of the public services it performs through its employees." Pickering v. Board of Educ., 391 U.S. 563, 568, 88 S.Ct. 1731, 1734, 20 L.Ed.2d 811 (1968). We briefly describe the precedents underlying each position before addressing the merits of the parties' claims.
A.
In Simon & Schuster, the Court unanimously struck down New York's "Son of Sam" law, which required that income from an accused or convicted criminal's description of his crime be turned over to a fund for compensation of the criminal's victims and creditors. In doing so, the Court noted that the law restricted the speech both of criminals seeking to write about their crimes and publishers, such as Simon & Schuster, that wished to publish such works. — U.S. at-, 112 S.Ct. at 508. Holding that from either perspective, the law "establishes a financial disincentive to create works with a particular content," the Court applied strict scrutiny. Id. at -, 112 S.Ct. at 509.
Almost twenty-five years earlier, in Pickering v. Board of Educ., 391 U.S. 563, 88 S.Ct. 1731, 20 L.Ed.2d 811 (1968), the Court used a deferential balancing test in a case brought by a discharged public school teacher. Ruling unanimously that the teacher could not be fired for having written a letter to the local newspaper criticizing the school board, the Court balanced "the interests of the teacher, as a citizen, in commenting upon matters of public concern and the interest of the State, as an employer, in promoting the efficiency of the public services it performs through its employees." Id. at 568, 88 S.Ct. at 1734-35. The rationale for not applying strict scrutiny was that "the State has interests as an employer in regulating the speech of its- employees that differ significantly from those it possesses in connection with regulation of the speech of the citizenry in general." Id.
B.
Appellants offer three arguments to support their claim that strict scrutiny, rather than the Pickering balancing test, applies here. They assert that Simon & Schuster required courts to apply strict scrutiny to all financial burdens on speech, regardless of whether the speaker is a public employee. In support of this contention, appellants cite a passage in Simon & Schuster stating that "[t]he Government's power to impose content-based financial disincentives on speech surely does not vary with the identity of the speaker." — U.S. at-, 112 S.Ct. at 509. Appellants claim this language mandates that we cannot apply a lower standard in the public employment context.
We reject this selective reading of Simon & Schuster. It is plain to us that the Court, by the quoted phrase, merely intended to make clear that it is no defense to a First Amendment claim that the claimant is not a member of the media. Putting the quoted statement in context shows this to be so:
Finally, the Board claims that even if the First Amendment prohibits content-based financial regulation specifically of the media, the Son of Sam law is different, because it imposes a general burden on any "entity" contracting with a convicted person to transmit that person's speech. This argument falters on both semantic and constitutional grounds. Any "entity" that enters into such a contract becomes by definition a medium of communication, if it wasn't one already. In any event, the characterization of an entity as a member of the "media" is irrelevant for these purposes. The Government's power to impose content-based financial disincentives on speech surely does not vary with the identity of the speaker.
Id. at-, 112 S.Ct. at 509 (citation omitted). Therefore, Simon & Schuster does not require the application of strict scrutiny to all financial disincentives on speech.
Appellants' next argument is that Pickering does not govern because the OGE/ EPA regulation does not simply restrict the speech of federal employees. The regulation, so the argument goes, also restricts the speech of nonemployees, such as NC WARN. In this respect, appellants analogize NC WARN to Simon & Schuster in that, as the publishers of the speech at issue, both were the targets of restrictions on speech. To that extent, appellants claim, strict scrutiny must be applied.
We likewise find this argument unpersuasive. Though it may be true that the OGE/EPA regulation affects the speech of third-parties outside of the Government's employ, such as NC WARN and amici, that was also true in Pickering. By firing the teacher for criticizing it, the school board in Pickering "chilled" teachers' speech critical of the board. Because the teacher's speech was directed (via his letter to the editor) to the local newspaper, the restriction on his speech also restricted the newspaper's speech, in that the newspaper intended to publish the teacher's letter and thereby "speak" against the school board. Despite this spillover restriction on nonemployee speech, Pickering applied a deferential balancing test. Thus, the spillover effect on NC WARN's speech, assuming such a restriction exists, does not defeat Pickering's applicability here.
Appellants' final contention is that Pickering does not apply to content-based and viewpoint-based restrictions on speech. We regard this argument as similarly foreclosed by reference to Pickering itself. The Court there expressly noted that "[t]he Board [had] dismissed Pickering for writing and publishing the letter," which "constituted, basically, an attack on the School Board's handling" of certain issues. 391. U.S. at 566, 88 S.Ct. at 1733. A more recent case applying the Pickering standard, Rankin v. McPherson, 483 U.S. 378, 107 S.Ct. 2891, 97 L.Ed.2d 315 (1987), supports this analysis. There, the Court applied Pickering even though the employee's termination was "based on the content of her speech," with which her supervisor strongly disagreed. Id. at 390, 107 S.Ct. at 2900. Pickering accordingly cannot be distinguished on the ground appellants urge.
We therefore adhere to our prior ruling that "Pickering and its progeny continue to be the meter by which the First Amendment rights of public employees are to be measured," Tygrett v. Barry, 627 F.2d 1279, 1282 (D.C.Cir.1980), and hold that the Pickering balancing test applies to appellants' First Amendment challenge.
III.
Because the familiar Pickering test is most often applied in employee discharge or discipline cases rather than in challenges to rules such as the OGE/EPA regulation, we set out the applicable standards at some length below. Before doing so, however, we observe that we must decide the Pickering balance de novo, without deferring to the balance the District Court struck. Hubbard v. EPA, 949 F.2d 453, 458 n. 2 (D.C.Cir.), vacated in part on other grounds, 982 F.2d 531 (D.C.Cir.1992) (en banc). This is so because this is a question of law. Hall v. Ford, 856 F.2d 255, 258 (D.C.Cir.1988).
A.
Because "the First Amendment's primary aim is the full protection of speech upon issues of public concern," Connick v. Myers, 461 U.S. 138, 154, 103 S.Ct. 1684, 1694, 75 L.Ed.2d 708 (1983), the Court must determine, as a threshold matter, whether the public employee's speech pertained to "matters of public concern." Id. at 146, 103 S.Ct. at 1689. Speech pertains to "matters of public concern" if it relates to "any matter of political, social, or other concern to the community." Id. If, judging from the "content, form, and context" in which the statement or speech was made, the speech does not so pertain, then "absent the most unusual circumstances," the Court may not proceed any further, for "a federal court is not the appropriate forum in which to review the wisdom of a personnel decision." Connick, 461 U.S. at 147, 103 S.Ct. at 1690; see also Hall, 856 F.2d at 258.
However, if the speech does pertain to matters of public concern, the Court must balance "the interests of the [employee], as a citizen, in commenting upon matters of public concern and the interest of the State, as an employer, in promoting the efficiency of the public services it performs through its employees." Pickering, 391 U.S. 563, 568, 88 S.Ct. 1731, 1734-35 (1968); see also Hall, 856 F.2d at 258. Harm to the governmental or state interest cannot be presumed, American Postal Workers Union, AFL-CIO v. United States Postal Serv., 830 F.2d 294, 304 n. 13 (D.C.Cir.1987); Tygrett v. Barry, 627 F.2d 1279, 1282 (D.C.Cir.1980), or based on "unadorned speculation." Hall, 856 F.2d at 261. Nevertheless, we and the Supreme Court have recognized that a government "employer is not required to tolerate action which [it] reasonably believed" would cause harm. Hubbard, 949 F.2d at 460 (quoting Connick, 461 U.S. at 154, 103 S.Ct. at 1694). "For regulation of employees it is not necessary that the act regulated be anything more than an act reasonably deemed . to interfere with the efficiency of the public service." United Public Workers v. Mitchell, 330 U.S. 75, 101, 67 S.Ct. 556, 570, 91 L.Ed. 754 (1947). And in some situations, "the circumstances and content of the speech [may] make unequivocal its harmful effects." American Postal Workers Union, AFL-CIO, 830 F.2d at 304 n. 12.
B.
Two of the above issues are not in question here. Appellees have conceded that appellants' speech about EPA policies pertained to matters of public concern. In addition, appellants do not challenge the legitimacy of the proffered governmental end—avoiding the appearance of impropriety. In our view, these were wise concessions. The parties do, however, sharply dispute the severity of the burden the regulation imposes on EPA employees' speech and, therefore, the balance of the competing interests of the Government and its employees in the EPA.
1.
The Employees' Interest
Appellants characterize the burden the OGE/EPA regulation imposes on their speech as "severe" because it is nothing short of an "economic bar to speech." Appellees dispute the severity of the regulation's burden on free speech, arguing that the strength of appellants' First Amendment interest is greatly reduced because the regulation allows them to speak whenever and on whatever topics they choose and merely prohibits EPA employees from accepting expense reimbursement. We find merit in this argument. As appellees correctly note, the OGE/EPA regulation does not prohibit speech in any way. EPA employees may speak now, as before, on whatever topics they choose. The rule only forbids EPA employees to obtain reimbursement from non-federal sources for speaking or writing in an unofficial capacity about their "official duties or on the responsibilities, policies and programs" of the agency. 5 C.F.R. § 2636.202(b). Although restricting reimbursement for unofficial speech does implicate the First Amendment, we cannot agree with appellants that the OGE/EPA regulation imposes a severe burden on the First Amendment rights of EPA employees. Rather, we view the burden in this regard as moderate, though not insignificant.
2.
The Government's Interest
As for the Government's side of the balance, appellants argue that the governmental interest underlying the OGE/EPA regulation is an illegitimate one—the suppression of unofficial speech. That is, they claim that the regulation is both content-based and viewpoint-based. As they view matters, and as the District Court agreed, 786 F.Supp. at 1037-38, EPA critics will be disproportionately disadvantaged by the OGE/EPA regulation because supporters, unlike critics, of EPA policy will probably be allowed to speak in an official capacity, thereby allowing supporters but not detractors of the EPA to receive travel-expense reimbursement. For this reason alone, appellants argue, the OGE/EPA regulation is "presumptively invalid" under the First Amendment. R.A.V. v. St. Paul, — U.S. -, -, 112 S.Ct. 2538, 2542, 120 L.Ed.2d 305 (1992) (citing cases).
Appellants' empirical assertion may or may not be correct, but, importantly, it is an empirical statement. Appellants forget that we have before us only a facial challenge to the OGE/EPA regulation. We must approach such challenges "with caution and restraint, as invalidation may result in unnecessary interference with a state [or federal] regulatory program." Erznoznik v. City of Jacksonville, 422 U.S. 205, 216, 95 S.Ct. 2268, 2276, 45 L.Ed.2d 125 (1975).
Given the nature of a facial challenge, appellants bear the heavy burden of showing that the OGE/EPA regulation "could never be applied in a valid manner" or is "so broad that it 'may inhibit the constitutionally protected speech of third parties.' " New York State Club Ass'n v. New York City, 487 U.S. 1, 11, 108 S.Ct. 2225, 2233, 101 L.Ed.2d 1 (1988) (quoting Members of the City Council of Los Angeles v. Taxpayers for Vincent, 466 U.S. 789, 798, 104 5.Ct. 2118, 2125, 80 L.Ed.2d 722 (1984)); see also Federal Election Comm'n v. International Funding Inst., Inc., 969 F.2d 1110, 1118 (D.C.Cir.1992) (en banc) (same); American Library Ass'n v. Barr, 956 F.2d 1178, 1190 (D.C.Cir.1992) (same). Consequently, "[a] facial challenge to a legislative Act is, of course, the most difficult challenge to mount successfully." United States v. Salerno, 481 U.S. 739, 745, 107 S.Ct. 2095, 2100, 95 L.Ed.2d 697 (1987).
The Supreme Court has explained these exceptions to the rule that "facial challenges to legislation are generally disfavored," FW/PBS, Inc., d/b/a Paris Adult Bookstore II v. City of Dallas, 493 U.S. 215, 224, 110 S.Ct. 596, 604, 107 L.Ed.2d 603 (1990):
Both exceptions, however, are narrow ones: the first kind of facial challenge will not succeed unless the court finds that "every application of the statute create[s] an impermissible risk of suppression of ideas," and the second kind of facial challenge will not succeed unless the statute is "substantially" overbroad, which requires the court to find "a realistic danger that the statute itself will significantly compromise recognized First Amendment protections of parties not before the Court."
New York State Club Ass'n, 487 U.S. at 11, 108 S.Ct. at 2233 (quoting Taxpayers for Vincent, 466 U.S. at 798 n. 15 & 801, 104 S.Ct. at 2125 n. 15 & 2126); see also City of Houston v. Hill, 482 U.S. 451, 458, 107 S.Ct. 2502, 2508, 96 L.Ed.2d 398'(1987) (holding that "[o]nly a statute that is substantially overbroad may be invalidated on its face"); Broadrick v. Oklahoma, 413 U.S. 601, 615, 93 S.Ct. 2908, 2917, 37 L.Ed.2d 830 (1973) (same). Either type of challenge must be made based on the face of the challenged statute or regulation. See Rust v. Sullivan, — U.S.-,-, 111 S.Ct. 1759, 1765, 114 L.Ed.2d 233 (1991); New York State Club Ass'n, 487 U.S. at 14, 108 S.Ct. at 2234 (same).
Based on their allegations in this case, appellants have attempted to make out the first type of facial challenge by showing that the text of the OGE/EPA regulation discriminates on the basis of viewpoint. However, it is obvious to us that no such discrimination appears on the face of the regulation. We find 40 C.F.R. § 3.503 (1991) quite instructive as it elucidates the otherwise elusive distinction between "official" and "unofficial" speech:
Writing, speaking, or editing is normally official if it results from a request to EPA to furnish a speaker, author or editor. If an invitation is addressed to an employee, the invitation is official if it is tendered because of the employee's EPA position rather than the employee's individual knowledge or accomplishments____ Otherwise, such activities are outside [presumably "unofficial"] activities.
Id. Section 3.503, in our view, means that, facially speaking, the EPA will not consider viewpoint in classifying speech as "official" or "unofficial." Though the official/unofficial distinction might be applied in the discriminatory manner appellants suggest, they must pursue that claim in the first instance, if at all, before the District Court, which correctly found that such a claim will turn on factual issues. See Fantasy Book Shop, Inc. v. City of Boston, 652 F.2d 1115, 1122 (1st Cir.1981).
There is, of course, a sense in which the OGE/EPA regulation may be said to be content-based. The regulation applies only to speech or writing that "focuses specifically on his official duties or on the responsibilities, policies and programs" of the EPA. 5 C.F.R. § 2636.202(b). We agree that the regulation is "content-based," in some sense, because it is "justified with[ ] reference to the content of the regulated speech," Virginia Pharmacy Bd. v. Virginia Citizens Consumer Council, Inc., 425 U.S. 748, 771, 96 S.Ct. 1817, 1830, 48 L.Ed.2d 346 (1976), but not in any meaningful sense.
Instead, we view the regulation as one that does not "fit neatly into either the 'content-based' or the 'content-neutral' category." Renton v. Playtime Theatres, Inc., 475 U.S. 41, 47, 106 S.Ct. 925, 929, 89 L.Ed.2d 29 (1986). One such category of restrictions of speech—and the one into which we think the OGE/EPA regulation falls—encompasses restrictions that are based on the content of speech but seek to regulate only the "secondary effects" of the speech. See R.A.V. v. St. Paul, — U.S. -, -, 112 S.Ct. 2538, 2546, 120 L.Ed.2d 305 (1992); Renton, 475 U.S. at 47-48, 106 S.Ct. at 928-29; Young v. American Mini Theatres, Inc., 427 U.S. 50, 96 S.Ct. 2440, 49 L.Ed.2d 310 (1976) (plurality opinion). Such a regulation is deemed content-neutral because it "serves purposes unrelated to the content of the expression." Ward v. Rock Against Racism, 491 U.S. 781, 791, 109 S.Ct. 2746, 2754, 105 L.Ed.2d 661 (1988); see also Renton, 475 U.S. at 48,106 S.Ct. at 929. Importantly, this remains so "even if [the restriction] has an incidental effect on some speakers or messages but not others." Rock Against Racism, 491 U.S. at 791, 109 S.Ct. at 2754.
We find the Supreme Court's decisions in Young, Renton and Rock Against Racism controlling and agree with appellees that the OGE/EPA regulation serves a purpose unrelated to the suppression of free speech—namely, avoiding the appearance of impropriety. In Pickering terms, avoiding the appearance of impropriety serves the further end of protecting the integrity and efficiency of the EPA's work force. Furthermore, we agree with appellees that this governmental interest is a "compelling" one. See Keeffe v. Library of Congress, 111 F.2d 1573, 1580-81 (D.C.Cir.1985) (holding that "preventfing] erosion of . public confidence in the integrity of the [public] [s]ervice" is a "compelling" governmental interest). While it may be true that the regulation might have a negative impact on EPA critics, we find that impact to be "incidental," given that the interest the regulation serves is wholly unrelated to the suppression of free speech. Rock Against Racism, 491 U.S. at 791, 109 S.Ct. at 2754. The District Court was thus correct in holding that the OGE/ EPA regulation is not content-based and that the relevant governmental interest is avoiding the • appearance of impropriety, not the suppression of unofficial speech.
Appellants' second argument for their facial challenge is that the OGE/EPA regulation is overbroad. Like appellants' first argument, this fits more neatly into the rubric of the first exception to the rule disfavoring facial challenges rather than the second. The First Amendment over-breadth doctrine is generally applied to challenges brought by plaintiffs who fall within the constitutionally permissible ambit of a restriction on speech, on behalf of third parties not before the court, as to whom the prohibition is unconstitutional. See, e.g., Moore v. City of Kilgore, 877 F.2d 364, 390-92 (5th Cir.1989). A court thus may not apply overbreadth analysis to a claim "that [a] statute is overbroad precisely because it applies to him—the plaintiff who is before us." Id.; see also New York State Club Ass'n v. New York City, 487 U.S. 1, 11, 108 S.Ct. 2225, 2233, 101 L.Ed.2d 1 (1988) (holding that "the second kind of facial challenge will not succeed unless the statute is 'substantially' over-broad, which requires the court to find 'a realistic danger that the statute itself will significantly compromise recognized First Amendment protections of parties not before the Court ' " (quoting Members of the City Council of Los Angeles v. Taxpayers for Vincent, 466 U.S. 789, 801, 104 S.Ct. 2118, 2126, 80 L.Ed.2d 772 (1984)) (emphasis added)). That is exactly the nature of appellants' "overbreadth" claim. See, e.g., Appellants' Br. at 35 (arguing that "the OGE rule blanketly, with no exception, prohibits [appellants Sanjour and Kaufman] from obtaining any reimbursements for this speech" sponsored by appellant NC WARN).
However, as the Supreme Court has recognized, the term "[o]verbreadth has also been used to describe a challenge to a statute that in all its applications directly restricts protected First Amendment activity and does not employ means narrowly tailored." Secretary of State of Maryland v. Joseph H. Munson Co., 467 U.S. 947, 967 n. 13, 104 S.Ct. 2839, 2852 n. 13, 81 L.Ed.2d 786 (1984). For that type of facial challenge to succeed, the plaintiff must carry the heavy burden of showing that the challenged statute or regulation is not narrowly tailored and that "there is no core of easily identifiable and constitutionally proscribable conduct that the statute prohibits." Id. at 965, 104 S.Ct. at 2851-52. Failing either showing, an overbreadth argument under the first type of facial challenge necessarily fails. See Parker v. Levy, 417 U.S. 733, 760, 94 S.Ct. 2547, 2563, 41 L.Ed.2d 439 (1974) (holding that courts must be "reluctant[ ] to strike down a statute on its face where there [are] a substantial number of situations to which it might validly be applied"); see also Ferber, 458 U.S. at 770 n. 25, 102 S.Ct. at 3362 n. 25 (same); Letter Carriers, 413 U.S. at 580-81, 93 S.Ct. at 2898 (same); Moore v. City of Kilgore, 877 F.2d 364, 391 (5th Cir.1989) (holding that courts should not facially invalidate overbroad statutes that "ha[ve] significant and lawful core application"). When the challenged statute does have a core of easily identifiable and constitutionally proscribable conduct, "the Court has required a litigant to demonstrate that the statute 'as applied' to him is unconstitutional." Munson, 467 U.S. at 965, 104 S.Ct. at 2851 (citing Ferber, 458 U.S. at 774, 102 S.Ct. at 3363). Because, as previously stated, we construe appellants' overbreadth argument to be a claim that the OGE/EPA regulation is not narrowly tailored for any purpose, we consider appellants' argument on the merits under the first exception to the rule against facial challenges.
Appellants correctly assert that any restriction on speech must be "narrowly drawn." McGehee v. Casey, 718 F.2d 1137, 1142-43 (D.C.Cir.1983) (quoting Brown v. Glines, 444 U.S. 348, 355, 100 S.Ct. 594, 600, 62 L.Ed.2d 540 (1980)); see also Williams v. IRS, 919 F.2d 745, 747 (D.C.Cir.1990) (per curiam). At least when a statute or regulation is content neutral, "the requirement of narrow tailoring is satisfied so long as the regulation promotes a substantial government interest that would be achieved less effectively absent the regulation" and "the means chosen are not substantially broader than necessary." Ward v. Rock Against Racism, 491 U.S. 781, 799-800,109 S.Ct. 2746, 2758, 105 L.Ed.2d 661 (1989) (internal quotation marks omitted). Appellants claim that the instant regulation violates this standard because no appearance of impropriety arises from being reimbursed for out-of-pocket expenses, and they dismiss appellees' argument to the contrary as nothing more than "unadorned speculation." We disagree with both their basic assertion and their dismissal of appellee's argument.
Appellants' claim that expense reimbursement necessarily cannot give rise to an appearance of impropriety is simply incorrect. We think it plain that expense reimbursement may create not just an appearance of impropriety, but actual impropriety. For example, suppose a non-federal organization invited an EPA employee to give an unofficial speech in Hollywood (as Sanjour did in 1989). Suppose further that the organization was willing to pay, via expense reimbursement, for the employee to fly first-class, stay at an exclusive resort, and dine at five-star restaurants.
Despite the extravagance of this employee's travel itinerary, appellants would have us believe that simply because at the end of the trip the employee is not enriched in monetary terms no appearance of impropriety has resulted. We disagree. It is plain to us that the employee is better off—he has received a valuable benefit based on the fact of his EPA employment—and that at least an appearance of impropriety may reasonably be said to result therefrom. Only by sheer formalism, ignoring both practical and economic effect, can it be argued that the employee has not received a valuable benefit. Consequently, even though a valuable benefit is conferred as "reimbursement" rather than as an outright gift, an appearance of impropriety can result from the acceptance of the benefit.
Once that rather obvious premise is established, it follows that the OGE/EPA regulation is not substantially overbroad and is "narrowly tailored" under Ward v. Rock Against Racism, 491 U.S. 781, 799-800, 109 S.Ct. 2746, 2758, 105 L.Ed.2d 661 (1989). As we have said, the regulation merely proscribes the receipt of expense reimbursement by unofficial speakers. Official speakers, by contrast, are allowed to receive expense reimbursement because, when employees speak in an official capacity (that is, present the views of the EPA), they are presumably under the watchful eye of the EPA. The same cannot be said as to unofficial speakers. When a benefit is paid in the open, subject to oversight by the responsible government officials, the public is reassured as to the legitimacy of the employee's receipt of the benefit. Even though the EPA does not totally control and oversee employees' acceptance of official travel reimbursement, it necessarily exercises more supervision over the activities of official speakers than it does over the similar activities of unofficial speakers. To give just one example, the employee decides for himself whether to accept an unofficial speaking invitation, but the EPA decides whether to provide an official speaker, even when an employee has received an official speaking invitation directly from a nonfederal source. See EPA Ethics Advisory 91-10, at 2 (Aug. 30, 1991). Because the EPA necessarily exer cises less control and oversight over unofficial speakers, the likelihood that an appearance of impropriety would arise by accepting unofficial expense reimbursement is correspondingly increased.
Moreover, the OGE/EPA regulation is narrowly tailored because it does not "burden substantially more speech than is necessary" to further the government's interest in avoiding the appearance of impropriety that, as just shown, may reasonably be said to result from accepting unofficial expense reimbursement. Ward v. Rock Against Racism, 491 U.S. 781, 799, 109 S.Ct. 2746, 2758, 105 L.Ed.2d 661 (1989). The appearance-of-impropriety reasoning applies with full force as long as the benefit the employee receives has some positive value. Even if we were to assume arguendo that the Government's asserted interest diminishes in substantiality and ultimately approaches zero weight in the Pickering balance as the benefit to which the regulation is applied decreases in value, we cannot agree with the dissent that it "throttles much valuable speech." Dissent at 331 (emphasis added).
As the size of the benefit approaches the inconsequential, the burden the OGE/EPA regulation imposes on First Amendment rights is correspondingly reduced. Potential unofficial speakers will be increasingly less "chilled" from giving unofficial speeches for inability to recover reimbursement for benefits of little value, such as "train fare and a few bites of casserole." Dissent at 326. Because of this phenomenon, any reduction in the weight of the Government's side of the Pickering balance is matched by a similar reduction on the employees' side, which means that the regulation may constitutionally be applied to trivial benefits and, as the dissent appears to concede, to benefits of considerable value as well. See Dissent at 327 (accepting reimbursement for benefits of considerable value "raise[s] an inference that the employee is travelling in luxury—receiving compensation in the form of fine dining and lush resort accommodations").
Altogether, the OGE/EPA regulation may constitutionally be applied to a wide variety of unofficial activities. The scope of its valid application exceeds the comparatively few cases where it might be unconstitutional to apply the regulation. In view of the foregoing, once it is established that public employee acceptance of benefits from entities outside the Government may reasonably be said to give rise to an appearance of impropriety, see supra pp. 315-16, and that the OGE/EPA regulation applies only where the employee has received a benefit, see 56 Fed.Reg. 1,721, 1,726 (1991) (to be codified at 5 C.F.R. § 2636.203(g) (1992)), the conclusion is inescapable that the OGE/EPA regulation is narrowly tailored on its face under Rock Against Racism. We therefore reject appellants' facial challenge asserting that the regulation can never be applied in a valid manner and hold that the OGE/EPA regulation is not substantially overbroad and is narrowly tailored. In sum, appellants' facial challenge, while asserting a species of "overbreadth," is unavailing under the first exception for the reasons set forth above and does not fit within the second exception.
The dissent's concerns that the OGE/ EPA regulation would forbid an employee to accept inconsequential benefits, such as "train fare and a few bites of casserole," Dissent at 326, are not properly addressed in a facial challenge. Those concerns depend on fact situations not before us (recall that in this case appellants were to receive all-expense-paid trips from Washington, D.C. to North Carolina). See American Library Ass'n v. Barr, 956 F.2d 1178, 1189 (D.C.Cir.1992) (holding that courts may not address issues unrelated to the particular facts of a facial challenge because "[t]he judicial power does not extend to issuing 'an opinion advising what the law would be upon a hypothetical state of facts' ") (quoting Aetna Life Ins. Co. v. Haworth, 300 U.S. 227, 241, 57 S.Ct. 461, 464, 81 L.Ed. 617 (1937)). Our insistence that only related factual circumstances be addressed in a facial challenge is grounded on more than a hypertechnical interpretation of Article III, for "[b]y focusing on the factual situation before us, and similar cases necessary for development of a constitutional rule, we face 'flesh-and-blood' legal problems with data 'relevant and adequate to an informed judgment.' " New York v. Ferber, 458 U.S. 747, 768, 102 S.Ct. 3348, 3360, 73 L.Ed.2d 1113 (1982) (footnotes and citations omitted). In addition, "[wjhatever hypotheticals plaintiffs [and the dissent] may devise are countered by other, equally plausible possibilities that negate their point." American Library Ass'n, 956 F.2d at 1189. Therefore, "whatever overbreadth may exist should be cured through case-by-case analysis of the fact situations to which [the regulation's] sanctions, assertedly, may not be applied," Broadrick v. Oklahoma, 413 U.S. 601, 615-16, 93 S.Ct. 2908, 2917-18, 37 L.Ed.2d 830 (1973), and appellants remain free on remand to adduce proof on precisely the type of issues the dissent raises.
Appellants' "unadorned speculation" argument reflects, we think, a misunderstanding of the quantum of proof required of the Government in Pickering eases. Neither we nor the Supreme Court have held that in a Pickering case, the Government must prove that a regulation on speech overlaps with the threatened harm to the governmental interest at stake with mathematical precision. Indeed, to place such a burden of proof on the government, which might well be insurmountable in cases where, as here, harm to the government interest is unquantifiable, would be flatly inconsistent with the settled notion that "the State has interests as an employer in regulating the speech of its employees that differ substantially from those it possesses in connection with regulation of the speech of the citizenry in general." Pickering v. Board of Educ., 391 U.S. 563, 568, 88 S.Ct. 1731, 1734, 20 L.Ed.2d 811 (1968). It would also be inconsistent with our prior recognition that "[v]alues are no less significant for being subtle, intangible and nonquantifiable." Henderson v. Lujan, 964 F.2d 1179, 1184 (D.C.Cir.1992).
To the contrary, we and the Supreme Court have accepted the government's claim of harm to the relevant governmental interest if it is "reasonably believed." See Connick v. Myers, 461 U.S. 138, 154, 103 S.Ct. 1684, 1694, 75 L.Ed.2d 708. (1983); Hubbard v. EPA, 949 F.2d 453, 460 (D.C.Cir.), vacated in part on other grounds, 982 F.2d 531 (D.C.Cir.1992) (en banc). That appellees' allegations of harm are reasonably believed is supported by the Highest Authority. As counsel for appellees stated in oral argument: "The biblical injunction is that you can't serve two masters." More precisely, "[n]o man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other." St. Matthew 6:24 (King James version).
The specter of EPA employees accepting valuable benefits from outside sources for unofficial activities raises the distinct possibility that they will appear to be (or actually will be) serving two masters, namely the public interest and their own pecuniary interest, to the detriment of the former. That scenario, it seems to us, must be reasonably believed; indeed, it may well, in itself, "make unequivocal its harmful effects." American Postal Workers Union, AFL-CIO v. United States Postal Serv., 830 F.2d 294, 304 n. 13 (D.C.Cir.1987). As we have held, "it is inescapable that some off-duty activities of a public servant are incompatible with the undivided loyalty and integrity that [such] a person must show." Keeffe v. Library of Congress, 777 F.2d 1573, 1580 (D.C.Cir.1985). On either theory, then, appellees have made an adequate showing of harm to the identified governmental interest, which we have found to be compelling.
3.
The Balance of the Competing Interests
We finally come to the balance of the competing interests. The OGE/EPA regulation does impose a burden on the First Amendment rights of EPA employees by preventing them from accepting reimbursement from non-federal sources for travel expenses incurred in giving unofficial speeches. However, that burden is but a moderate one because EPA employees are allowed to speak on any subject matter they choose. At the same time, the regulation serves the compelling governmental end of promoting the integrity and efficiency of the EPA's work force by avoiding the appearance of impropriety that may reasonably be said to result from the employees' acceptance of travel-expense reimbursements (or other forms of compensation) from non-federal sources. In light of this, we hold that the Pickering balance tilts decidedly in appellees' favor.
IV.
In addition to their overinclusiveness challenge, appellants urge the under-inclusiveness of the OGE/EPA regulation as an independent basis for striking it down. They claim that if accepting non-federal expense reimbursement for unofficial speech creates an appearance of impropriety, so does accepting such reimbursement for official speech. Because the regulation prohibits only the former and not the latter, appellants claim, the regulation is underinclusive and therefore is not "narrowly tailored."
Neither argument is well taken. First, to make out their underinclusiveness claim, appellants must do more than show that the OGE/EPA regulation applies only to unofficial but not official speakers. They must show that the OGE and the EPA could not "reasonably conclude" that accepting reimbursement for official speech "presents sufficiently less likelihood of the harms sought to be prevented to justify [its] differential treatment." Fantasy Book Shop, Inc. v. City of Boston, 652 F.2d 1115, 1121 n. 6 (1st Cir.1981). Appellants have failed to meet that burden in this case. When an EPA employee speaks in an official capacity, he is presumably under the watchful eye of the EPA because it has sent him to present its views, much like a mouthpiece for the agency. See 40 C.F.R. § 3.503 (1991). Unofficial EPA speakers, however, are not sent by the EPA, which raises the prospect that by accepting travel reimbursement, they are attempting to trade on their public office for personal gain. See supra at 315-16. The OGE and the EPA, therefore, could reasonably conclude that accepting reimbursement for unofficial activities may create a greater appearance of impropriety than accepting reimbursement for official activities.
Second, even if the OGE/EPA regulation is underinclusive for the reason appellants suggest, that fact standing alone does not render the regulation unconstitutional. As we read the relevant cases, we may not invalidate a statute or regulation on First Amendment grounds just because it is underinclusive. Rather, we may do so only if the underinclusiveness clearly gives rise to an inference that the real motivation behind the statute or regulation is the suppression of speech. See, e.g., Florida Star v. B.J.F., 491 U.S. 524, 540, 109 S.Ct. 2603, 2612, 105 L.Ed.2d 443 (1989) (holding that "facial underinclusiveness . raises serious concerns about whether [the State] is, in fact, serving, with this statute, the significant interests which appellee invokes"); FCC v. League of Women Voters of California, 468 U.S. 364, 396, 104 S.Ct. 3106, 3126, 82 L.Ed.2d 278 (1984) (striking down statute banning noncommercial educational broadcasting stations from "editorializing" because its underinclusiveness "undermines the likelihood of a genuine governmental interest in preventing private groups from propagating their owns views via public broadcasting") (brackets and internal quotation marks omitted); Erznoznik v. City of Jacksonville, 422 U.S. 205, 214-15, 95 S.Ct. 2268, 2275, 45 L.Ed.2d 125 (1975) (invalidating as "strikingly underinclusive" ordinance forbidding the showing of nudity in drive-in theaters because the City's justification was patently pretextual); News America Pub., Inc. v. FCC, 844 F.2d 800, 815 (D.C.Cir.1988) (striking down statutory amendment precluding the FCC from renewing plaintiff's waiver of the ban on simultaneously owning a newspaper and television station in the same city because "the only 'evil' that the Amendment scotched was the possibility that [Rupert] Murdoch [(plaintiff's owner)] might get extensions").
Where the underinclusiveness does not clearly imply a censorial motive, we must reject the underinclusiveness claim as long as the statute or regulation actually furthers the proffered speech-neutral governmental interest. See, e.g., Ward v. Rock Against Racism, 491 U.S. 781, 799-800, 109 S.Ct. 2746, 2758, 105 L.Ed.2d 661 (1989) (holding that "the requirement of narrow tailoring is satisfied so long as the . regulation promotes a substantial government interest that would be achieved less effectively absent the regulation" and "the means chosen are not substantially broader than necessary") (internal quotation marks omitted); Posadas de Puerto Rico Assocs. v. Tourism Co., 478 U.S. 328, 342-43, 106 S.Ct. 2968, 2977, 92 L.Ed.2d 266 (1986) (upholding statute banning advertisement of casino gambling but not other types of gambling because "whether or not other kinds of gambling are advertised, the restrictions on the advertising of casino gambling 'directly advance' the legislature's interest"); Renton v. Playtime Theatres, Inc., 475 U.S. 41, 52-53, 106 S.Ct. 925, 931-32, 89 L.Ed.2d 29 (1986) (upholding ordinance preventing the operation of adult movie theaters within 1,000 feet of homes, churches and schools because its underinclusiveness "in no way suggests that the city has 'singled out' adult theaters for discriminatory treatment").
With these principles in mind, we find persuasive the recent decision of the Sixth Circuit in Ater v. Armstrong, 961 F.2d 1224 (6th Cir.), cert. denied, — U.S.-, 113 S.Ct. 493, 121 L.Ed.2d 431 (1992). In Ater, a Kentucky statute, justified as ensuring the safe and orderly flow of traffic, prohibited people from standing in the roads and on the medians between roads. However, the same statute excepted standing in either place for the purpose of soliciting funds, as long as a police or other public safety vehicle was present to aid the flow of traffic. The police informed Ater, a Grand Dragon of the Realm of the Kentucky Invisible Empire, Knights of the Ku Klux Klan ("KKK"), that the statute barred him from distributing KKK literature on or along the roads. Ater filed suit, claiming, inter alia, that the statute was underinclusive for its asserted purpose in that it allowed roadside solicitation but not leafleting.
The Sixth Circuit rejected Ater's underinclusiveness claim, citing Ward v. Rock Against Racism, 491 U.S. 781, 800, 109 S.Ct. 2746, 2758, 105 L.Ed.2d 661 (1989), for the proposition that the statute was narrowly tailored, even though it was underinclusive. In spite of the statute's underin elusiveness, the court of appeals upheld the statute as "intended to promote the legitimate goal of safety in the roadways." Ater, 961 F.2d at 1229. It explained:
By prohibiting the distribution of literature in the roadways, the statute eliminates no more activity than was considered necessary____ Although this statute presents an underinclusive remedy, it clearly serves the state's interest in avoiding traffic congestion and fostering road safety. It cannot be doubted that Kentucky has the power to limit pedestrian activities upon its roadways. We cannot believe, as the dissent apparently would have us hold, that Kentucky prohibited nearly all forms of pedestrian activity upon its roads, excepting only solicitation, because it wished to censor expression. Its reason clearly was safety
Id. at 1229-30. The court also rejected the proposition that the court should "require a legitimate government interest that justifies the exception of solicitation from the general proscription of pedestrian activity on the roads," holding that
The legitimate government interest need only justify the general prohibition of protected activity; so long as its distinctions are content neutral, it need not justify the allowance of some expression____ Unless a prohibition is content based, we examine the legislature's motive for prohibiting the forms of conduct it chooses to prohibit, not its motive for excepting other forms of conduct from the prohibition.
Id. at 1230 n. 5 (emphasis added); see also Walsh v. Brady, 927 F.2d 1229, 1238 (D.C.Cir.1991) (Williams, J., concurring) (stating that "it surely cannot be the case that as a general matter the Constitution militates in favor of keeping content-neutral exemptions from free speech bans as narrow as possible").
As applied to the case before us, Ater means that the OGE/EPA regulation's possible underinclusiveness is irrelevant if (1) it is content-neutral and (2) its ban on reimbursement for travel expenses incurred during unofficial activities furthers the proffered interest in avoiding the appearance of impropriety. See Ater, 961 F.2d at 1229-30 & n. 5. As our prior discussion makes clear, the regulation satisfies both conditions. First, the regulation is content-neutral. It merely regulates the secondary effects of accepting unofficial travel-expense reimbursement. See R.A.V. v. St. Paul, — U.S.-,-, 112 S.Ct. 2538, 2546, 120 L.Ed.2d 305 (1992); Ward v. Rock Against Racism, 491 U.S. 781, 791, 109 S.Ct. 2746, 2754, 105 L.Ed.2d 661 (1988); Renton v. Playtime Theatres, Inc., 475 U.S. 41, 106 S.Ct. 925, 89 L.Ed.2d 29 (1986); Young v. American Mini Theatres, Inc., 427 U.S. 50, 96 S.Ct. 2440, 49 L.Ed.2d 310 (1976) (plurality opinion).
Second, we are confident that the OGE/ EPA regulation, despite its claimed under-inclusiveness, serves the asserted interest in avoiding the appearance of impropriety resulting from accepting valuable benefits from non-federal sources for unofficial activities. Accepting such compensation is the root cause of such an appearance, regardless of whether the same is true of official expense reimbursement. We add only that "[w]e simply have no basis on this record for assuming that" the EPA will not amend the OGE/EPA regulation to apply to official expense reimbursement as well if it later proves to be the source of a similar appearance of impropriety. Renton, 475 U.S. at 52, 106 S.Ct. at 931. Therefore, under the principles we announce today, in harmony with Ater v. Armstrong, 961 F.2d 1224 (6th Cir.1992), and the Supreme Court cases discussed above, appellants' claim that the OGE/EPA regulation is underinclusive, even if true, is insufficient reason to sustain their facial challenge.
To summarize, the regulation is narrowly tailored to serve a compelling governmental interest—avoiding the appearance of impropriety that may reasonably be said to result from acceptance of non-federal expense reimbursement for unofficial speech or writing. That government interest, which is unrelated to the suppression of speech, outweighs EPA employees' moderate First Amendment interest in receiving compensation for unofficial speech. Accordingly, under Pickering, we hold that the OGE/EPA regulation does not facially violate the First Amendment.
CONCLUSION
Lest our mandate be misunderstood, we again emphasize the narrowness of our holding today. We do not uphold the OGE/EPA regulation against all First Amendment attack. Rather, we merely hold that the regulation is not unconstitutional on its face, based on the claims put to us. As much as appellants have tried to convince us otherwise, the OGE/EPA regulation is neither facially content-based nor viewpoint-based. Although it is possible that the EPA might selectively apply the regulation in order to suppress the unofficial speech of its critics, appellants remain free, should they have any proof of this, to pursue that claim in the District Court.
Affirmed and remanded.
.More fully, the new OGE rule provides, in pertinent part, that:
(b) An employee is prohibited by the standards of conduct from receiving compensation, including travel expenses, for speaking or writing on subject matter that focuses specifically on his official duties or on the responsibilities, policies and programs of his employing agency.
5 C.F.R. § 2636.202(b). None of the rule's terms are defined. However, to clarify any ambiguity, employees may request advisory opinions from their employing agencies' ethics officials. 5 C.F.R. § 2636.103. Good-faith compliance with such advisory opinions immunizes the employee from civil or disciplinary action by the OGE. 5 C.F.R. § 2636.103(c).
. Hereinafter, we refer to the OGE regulation and EPA Ethics Advisory 91-1 collectively as the "OGE/EPA regulation."
. Our dissenting colleague thus addresses an issue not properly before us in arguing that "there are no precise standards to cabin the EPA's discretion." Dissent at 330 n. 12. The closest appellants came to raising that claim is a point heading in their initial brief asserting that the OGE/EPA regulation is "unconstitutionally vague," Appellants' Br. at i, a claim they repeated verbatim in the conclusion to that section. Id. at 36. Their only "explication" in the argument is that "the OGE rules gives [sic] an agency the unfettered discretion to declare any proposed speech 'official.'" Id. at 35. The vagueness/unfettered-discretion claim is not otherwise mentioned, and appellants cited no authority in support of that claim. Unsurprisingly, therefore, neither the District Court's thorough opinion nor appellees' brief addresses the question.
Under these circumstances, we decline to address appellants' vagueness/unfettered-discretion argument. "Judges are not like pigs, hunting for truffles buried in briefs." United States v. Dunkel, 927 F.2d 955, 956 (7th Cir.1991) (per curiam). Nevertheless, we note that the OGE/ EPA regulation contains provisions for remedying ambiguity in its applicability {see note 1, supra), see United States Civil Serv. Comm'n v. National Ass'n of Letter Carriers, AFL-CIO, 413 U.S. 548, 580, 93 S.Ct. 2880, 2897-98, 37 L.Ed.2d 796 (1973) (deeming it "important," in rejecting a similar challenge, "that the Commission has established a procedure by which an employee in doubt about the validity of a proposed course of conduct may seek and obtain advice from the Commission and thereby remove any doubt there may be as to the meaning of the law"), as well as definitions of the terms "official" and "unofficial." See 40 C.F.R. § 3.503 (1991).
. We, like the Hubbard panel, need not decide whether deference is owed the underlying factual determinations of the District Court.
. The dissent criticizes as formalistic our conclusion that the burden the OGE/EPA regulation imposes only a moderate burden on employee speech. See Dissent at 322-23. We respectfully disagree. Quite clearly, a restriction on accepting reimbursement for speaking is significantly less burdensome than an outright ban on speech. A ban prohibits speech and leaves the employee, to use the dissent's term, "gagged." A restriction on reimbursement, such as the OGE/EPA regulation, leaves the employee free to speak whenever and on whatever topics he chooses, even though it allows reimbursement. for other types of speech. Far from being formalistic, the distinction we have drawn is true to the Supreme Court's admonition that '"[t]here is a basic difference between direct state interference with a protected activity and state encouragement of an alternative activity.' " Rust v. Sullivan, — U.S. -, -, 111 S.Ct. 1759, 1772, 114 L.Ed.2d 233 (1991) (quoting Maher v. Roe, 432 U.S. 464, 475, 97 S.Ct. 2376, 2383, 53 L.Ed.2d 484 (1977)).
. We, of course, express no opinion whatsoever on the merit of appellants' as-applied challenge. We note, however, that the concerns the dissent raises in the facial challenge before us—for example, that the OGE/EPA regulation cannot constitutionally apply to "a federal employee addressing a church supper in return for train fare and a few bites of casserole," Dissent at 326—are more appropriately dealt with in an as-applied challenge. See infra at 316-17.
. Far from being caught "between a rock and a hard place," Dissent at 329 n. 12, we believe we are on solid ground in holding that the OGE/ EPA regulation does not discriminate facially on the basis of viewpoint. In any event, "it is difficult to see how any government employer could regulate speech without, more or less directly, carving out an exception for speech approved by the employer. Employees will sometimes have to act as spokespeople." Moore v. City of Kilgore, 877 F.2d 364, 393 (5th Cir.1989). Consistent with this realization, all the OGE/ EPA regulation does is allow travel-expense reimbursement for the EPA's spokespeople, but not for employees—be they EPA supporters or critics—who do not speak for the EPA. The dissent's argument that the OGE/EPA regulation allows "the government's side [of the debate over EPA policies] . open access to particular audiences and forms of expression but [denies such access to] employees who seek to speak from other perspectives," Dissent at 330, fails to recognize this last point—that unofficial speakers may be supporters or critics of the EPA—and the related point that official speech is not necessarily aimed at touting the policies of the EPA.
. We do not here attempt a blanket definition of content-neutrality. Rather, we merely note the Supreme Court's reasoning in treating secondary-effects restrictions as content-neutral. Aside from secondary-effects restrictions, we have stated that 'lack of government disagreement with the message is a necessary condition for content neutrality, [but] it is not in all cases a sufficient one." Christian Knights of the Ku Klux Klan Invisible Empire, Inc. v. District of Columbia, 972 F.2d 365, 373 (D.C.Cir.1992) (citing cases).
. In reaching this conclusion, we have considered and rejected appellants' contention that the OGE/EPA regulation is fatally underinclusive. We defer discussion of that issue, however, until Part IV of this opinion. See infra at 318-21.
. In other words, although a party who believes a statute unconstitutionally restricts his own conduct can argue that the statute is over-broad as applied to third parties, we do not read appellants' brief as raising that type of facial challenge. Even if they had, we rather doubt that the OGE/EPA regulation is substantially overbroad. See infra at 316. As we read the somewhat confusing overinclusiveness section of appellants' brief, they really claim that the nexus between the asserted government interest and the regulation is so inexact that the regulation is substantially overbroad in all its applications—the first type of facial challenge.
. We recognize that the Munson Court applied the latter formulation in the context of the assertion of third-party rights under the second type of facial challenge, but we fail to discern any analytical reason for restricting that burden to the third-party context. As Munson explained, the judicial reluctance to invalidate a statute on its face "is appropriate in cases where, despite some possibly impermissible application, the remainder of the statute . covers a whole range of easily identifiable and constitutionally proscribable . conduct." 467 U.S. at 964-65, 104 S.Ct. at 2851 (ellipses in original; internal quotation marks omitted). That analysis is applicable regardless of whose rights are being asserted, as the Munson Court's citation, in support of the proposition quoted above, of two cases not involving the assertion of third-party rights indicates. See 467 U.S. at 965, 104 S.Ct. at 2851 (citing New York v. Ferber, 458 U.S. 747, 770 n. 25, 102 S.Ct. 3348, 3362 n. 25, 73 L.Ed.2d 1113 (1982) (challenge by owner of adult bookstore which rented pornographic films involving children to constitutionality of state statute criminalizing selling or otherwise promoting child pornography); United States Civil Serv. Comm'n v. National Ass'n of Letter Carriers, AFL-CIO, 413 U.S. 548, 580-81, 93 S.Ct. 2880, 2898, 37 L.Ed.2d 796 (1973) (challenge by federal employees and federal employees union, inter alia, to constitutionality of federal statute restricting political activities of federal employees)).
. Despite our use of the above hypothetical, we do not contend that a single hypothetical, standing alone, in which the regulation can constitutionally be applied, proves the OGE/EPA is narrowly tailored. The hypothetical is offered simply to refute appellants' argument that expense reimbursement can never give rise to an appearance of impropriety, a contention even the dissent does not endorse.
. Although the dissent asserts that underinclusiveness is germane to the weight on the government's end of the Pickering scale, see Dissent at 327, none of these cases were Pickering cases. As cases involving restrictions on the speech of the citizenry, the Supreme Court performed no balancing test and could not have meant to establish to what degree, if any, underinclusiveness entitles the proffered governmental interest to less weight vis-a-vis the First Amendment rights of public employees. Pickering cases are different, both in kind and in degree, from cases involving restrictions on the speech of people outside the Government's employ. See, e.g., Connick v. Myers, 461 U.S. 138, 154, 103 S.Ct. 1684, 1694, 75 L.Ed.2d 708 (1983) (holding that "the Government, as an employer, must have wide discretion and control over the management of its personnel and internal affairs") (internal quotation marks omitted); Cafeteria & Restaurant Workers Union, Local 473, AFL-CIO v. McElroy, 367 U.S. 886, 896, 81 S.Ct. 1743, 1749, 6 L.Ed.2d 1230 (1961) (sharply distinguishing between the "governmental function[s]" of exercising the power "to regulate or license, as lawmaker" and "as proprietor, to manage the [government's] internal operation[s]"). We note again that "the State has interests as an employer in regulating the speech of its employees that differ significantly from those it possesses in connection with regulation of the speech of the citizenry in general." Pickering v. Board of Educ., 391 U.S. 563, 568, 88 S.Ct. 1731, 1734, 20 L.Ed.2d 811 (1968).
Even if the underinclusiveness cases discussed above are applicable in Pickering cases, it is clear to us that the Court did not consider underinclusiveness in determining whether the proffered state interest was "compelling," as the dissent argues. Instead, the Court merely considered the claimed underinclusiveness to decide whether or not the government was in fact serving the proffered interest with the challenged statute or regulation.
. The dissent's attempt to distinguish Ater on the basis that "the regulation distinguished only between types of speech—soliciting funds was allowed on roadways, but other forms of speech were not," Dissent at 330 n. 13, thus is unavailing. The OGE/EPA regulation, like the statute in Ater, distinguishes between types of speech— namely, "official" and "unofficial" speech, a categorization which is, on its face, both content- and viewpoint-neutral. See supra at 312-13.
. We have applied these cases here even though they were not Pickering cases, but we emphasize that constitutional scrutiny of restrictions on the speech of public employees is significantly less demanding than the scrutiny applied to restrictions on the speech of citizens. For example, outside of the public employment context, content-based restrictions on speech are subject to the strictest of judicial scrutiny, Simon & Schuster v. Members of the New York State Crime Victims Bd., — U.S.-, 112 S.Ct. 501, 116 L.Ed.2d 476 (1991), and are "presump tively invalid." R.A.V. v. St. Paul, — U.S.-, -, 112 S.Ct. 2538, 2542, 120 L.Ed.2d 305 (1992). However, as we made clear above, restrictions on the speech of public employees are subject only to the deferential Pickering balancing test. Connick v. Myers, 461 U.S. 138, 103 S.Ct. 1684, 75 L.Ed.2d 708 (1983); Pickering v. Board of Educ., 391 U.S. 563, 88 S.Ct. 1731, 20 L.Ed.2d 811 (1968). Further examples could be provided, but the point is clear—because restrictions on public employees' speech are inherently less suspect than restrictions on the speech of the citizenry, id. at 568, 88 S.Ct. at 1734, courts must apply less rigorous First Amendment scrutiny to the former than to the latter.