LOS ANGELES (AP) — The Justice Department on Thursday sued to block new congressional district boundaries approved by California voters last week, joining a court battle that could help determine which party wins control of the U.S. House in 2026.

The complaint filed in California federal court targets the new congressional map pushed by Democratic Gov. Gavin Newsom in response to a similar Republican-led effort in Texas backed by President Donald Trump. It sets the stage for a high-stakes legal and political fight between the Republican administration and the Democratic governor, who’s seen as a likely 2028 presidential contender.

“California’s redistricting scheme is a brazen power grab that tramples on civil rights and mocks the democratic process,” Attorney General Pam Bondi said in an emailed statement. “Governor Newsom’s attempt to entrench one-party rule and silence millions of Californians will not stand.”

California voters overwhelmingly approved Proposition 50, a constitutional amendment changing the congressional boundaries to give Democrats a shot at winning five seats now held by Republicans in next year’s midterm elections.

The Justice Department is joining a case challenging the new map that was brought by the California Republican Party last week. The Trump administration accuses California of racial gerrymandering in violation of the Constitution by using race as a factor to favor Hispanic voters with the new map. It asks a judge to prohibit California from using the new map in any future elections.