In the case of Beer et al. v. United States et al., 1975, the U.S Supreme Court ruled on a dispute regarding changes to electoral districts in New Orleans, Louisiana. The city had redrawn its district lines following population shifts recorded in the 1970 census; however, these new boundaries were challenged under Section 5 of the Voting Rights Act (VRA) of 1965 which requires certain jurisdictions with a history of racial discrimination to obtain federal approval before changing voting procedures or practices ("preclearance"). The plaintiffs argued that although minority representation was not reduced by redistricting, it failed to enhance their political power proportionate to their increased population and thus constituted "retrogression". However, the court held that Section 5 only prohibits measures that lead to a retrogressive effect on minorities' ability to elect representatives of their choice compared with pre-existing law - it does not mandate maximization or enhancement of minority voting strength. Therefore, since there was no reduction in existing levels of minority representation due solely from redistricting itself as alleged by plaintiffs but rather an increase albeit less than proportional growth rate among blacks within those districts - preclearance could be granted without violating VRA provisions.

In the dissenting opinion for Beer et al. v. United States et al., Justice Brennan, joined by Justices White and Marshall, argued that the majority's interpretation of Section 5 of the Voting Rights Act was incorrect. They contended that any voting procedure change should not be permitted if it has a discriminatory effect on minority voters, regardless of whether or not it increases or decreases pre-existing discrimination levels. The dissenters believed this approach to be more in line with Congress' intent when drafting the legislation - to eliminate all forms of racial discrimination in voting procedures rather than merely preventing an increase in such discrimination. They also criticized the majority's reliance on legislative history as evidence for their interpretation, arguing instead that clear statutory language should guide judicial interpretations.