A coalition of California voters and the state’s Republican Party filed a federal lawsuit Wednesday challenging the legality of Proposition 50’s congressional redistricting maps.

The lawsuit argues that Proposition 50 constitutes unlawful racial gerrymandering in violation of the Fourteenth and Fifteenth Amendments. The suit targets 16 congressional districts that, according to the complaint, legislators have explicitly characterized as “Voting Rights Act districts” designed to “empower Latino voters to elect their candidates of choice.”

The lawsuit calls on Supreme Court precedent that requires race-based districting to meet strict standards. Under Cooper v. Harris and Miller v. Johnson, states must demonstrate that they relied on strong evidence that race-conscious districting was necessary in order to comply with the Voting Rights Act.

The plaintiffs contend that Proposition 50 used explicit racial criteria without requisite necessity, in violation of constitutional mandates of racial neutrality in governmental decision-making. The complaint also argues that under Thornburg v. Gingles, California has failed to show that its minority population’s preferred candidates have been unable to win elections due to the concerted opposition of a racial majority population.

The lawsuit requests a three-judge court under 28 U.S.C. § 2284 and seeks declaratory and injunctive relief invalidating the new maps.

This marks the latest development in ongoing disputes over voting rights, following similar disputes over racial districting in Louisiana and New York.

Proposition 50, which passed Tuesday’s California special election, redraws congressional district maps starting in 2026. Proponents of Proposition 50, including Governor Gavin Newsom, argue that redistricting is necessary to maintain Voting Rights Act compliance while defending California’s congressional representation against what has been characterized as partisan Republican redistricting efforts in states like Texas.