SACRAMENTO, Calif. (AP) — California Republicans filed a federal lawsuit Wednesday to block a new U.S. House map that California voters decisively approved at the ballot.

Proposition 50, backed by Democratic Gov. Gavin Newsom, is designed to help Democrats flip as many as five congressional House seats in the midterm elections next year. The lawsuit claims the map-makers improperly used race as a factor to favor Hispanic voters “without cause or evidence to justify it,” and asks the court to block the new boundaries ahead of the 2026 elections. The complaint, filed in the U.S. District Court for the Central District of California, is funded by the National Republican Congressional Committee.

The Supreme Court has ruled that “states may not, without a compelling reason backed by evidence that was in fact considered, separate citizens into different voting districts on the basis of race,” the lawsuit says.

There have been two analyses showing there were no voting rights problems that warranted the redrawing of the map, it adds.

The complaint was filed by The Dhillon Law Group, the California-based firm started by Harmeet Dhillon, who is now an assistant attorney general for civil rights at the U.S. Department of Justice.

The lawsuit also alleges that state lawmakers and a mapmaking consultant admitted in public statements that they intentionally redrew some districts to have a Latino majority. In one of the press releases from state Democrats, lawmakers said that the new map “retains and expands Voting Rights Act districts that empower Latino voters” while making no changes to Black majority districts in the Oakland and Los Angeles areas, the lawsuit says.

“The map is designed to favor one race of California voters over others,” Mike Columbo, whose plaintiffs include a state Republican lawmaker and 18 other voters, said at a news conference Wednesday. “This violates the 14th Amendment’s guarantee of equal protection under the law, and the right under the 15th Amendment.”