Whether a federal court may adjudicate a challenge to population disparities among congressional districts, or whether the issue is a nonjusticiable political question committed exclusively to Congress.
Holding
Yes. A challenge alleging that unequal congressional districts dilute the weight of a citizen's vote presents a justiciable constitutional claim.
Reasoning
The Court treated Baker v. Carr as controlling on the threshold question. Baker held that voters could bring a justiciable claim challenging population disparities in state legislative districts, and the same vote-debasement injury was alleged here with respect to congressional elections.
The Court also emphasized that prior decisions—especially Smiley v. Holm, Koenig v. Flynn, and Carroll v. Becker—had already established that congressional-redistricting disputes can be adjudicated. Justice Frankfurter's contrary view in Colegrove v. Green, that such questions belonged exclusively to Congress, had not commanded a majority of the Court.
Article I, § 4 gives Congress authority to make or alter state regulations governing congressional elections, but it does not strip courts of their ordinary duty to protect individual constitutional rights. The right to vote for Representatives is too fundamental to be left without judicial protection merely because Congress also has regulatory power.
The district court could not avoid deciding the claim by describing its dismissal as one for “want of equity” rather than nonjusticiability. Its rationale rested on the same generalized political-question concerns rejected by Baker, rather than on case-specific equitable circumstances.