al population, used to ensure districts are of equal population, and voting-age population, to ensure compliance with the Voting Rights Act. In the DistrictBuilder software, we have made available the voting-age population data by race and ethnicity. (The issue of citizen-voting age population is a complicated one; more on this soon.)
There are two important sections of the Voting Rights Act that apply to the creation of minority opportunity districts, Section 2 and Section 5.
Section 2 applies nationally. Essentially, Section 2 requires that if there is racially polarized voting and if a minority opportunity district can be drawn, then it must be drawn. (There is a further consideration, known as the "totality of the circumstances," which involves the history of past discrimination in the jurisdiction in question.)
Section 5 applies only to covered jurisdictions. These jurisdictions must clear any electoral change -- from moving a polling place to redistricting -- with the Department of Justice or the District Court of DC before it can take effect. (The Department of Justice is the overwhelming pathway of choice.) This federal oversight is intended to ensure that a change does not have a discriminatory effect. In the context of redistricting, Section 5 requires that the number of minority opportunity districts cannot decrease during redistricting. This is called retrogression.
The Department of Justice has 60 days to review a redistricting plan to ensure compliance with Section 5. It may request another 60 days for additional review. If a redistricting plan is not cleared in a timely manner, or worse it is rejected and the state or locality has insufficient time to correct deficiencies, courts may impose their own plans for use in the next election. State law may allow or forbid a subsequent "re-redistricting." Because Section 5 only applies to covered jurisdictions, federal courts are not required to clear their plans before they take effect.
The Department of Justice has released "Guidance Concerning Redistricting Under Section 5 of the Voting Rights Act." To underscore the importance of the Public Mapping Project to minority voting interests, the Department of Justice states
Thus, plans drawn by the public may factor into the Department of Justice's decision to approve a redistricting plan submitted by a covered jurisdiction.
What Is Required in Practice
In practice, Section 2 and Section 5 essentially require that at least the same number of minority opportunity districts in a previous redistricting plan must be drawn in a new redistricting plan. Section 5 explicitly requires this, and Section 2 has been litigated in most parts of the country. There are two exceptions:
It is beyond the capabilities of most ordinary citizens -- and sometimes even redistricting authorities! -- to comply with all the intricacies of the Voting Rights Act. To provide clues as to whether or not your districts are in compliance, on the statistics sidebar on the righthand side of the plan editor, we report the number of districts with more than 50% minority voting-age population (VAP) in the plan used for the previous decade and the number in the plan you are drawing. Typically, you should have at least the same number in your plan as in the previous plan.