California Gov. Gavin Newsom speaks during an election night press conference at a California Democratic Party office Tuesday in Sacramento, Calif. (AP Photo/Godofredo A. Vásquez)

LOS ANGELES (AP) — California voters approved new congressional district boundaries Tuesday, delivering a victory for Democrats in the state-by-state redistricting battle that will help determine which party wins control of the U.S. House in 2026 and, with it, the power to thwart or advance President Donald Trump’s agenda.

The approval of Proposition 50 gives Democrats a shot at winning as many as five additional seats, just enough to blunt Texas Republicans’ move to redraw their own maps to pick up five GOP seats at Trump’s urging. Texas’ move and California’s response have kicked off a flurry of redistricting efforts around the country, with Republican states appearing to have an edge. Deeply blue California is Democrats’ best opportunity to make up seats.

Midterm elections typically punish the party in the White House, and Trump is fighting to maintain his party’s slim House majority. Republicans hold 219 seats to Democrats’ 213.

Tuesday’s results mark a political victory for Democratic Gov. Gavin Newsom, who cast the measure as an essential tool to fight back against Trump and protect American democracy.

Speaking to reporters in Sacramento, Newsom cast the California vote as part of a broader national rejection of Trump’s policies that saw Democratic governors elevated in New Jersey and Virginia. But he warned the more consequential battle would come next year.

If Democrats win the House majority, they can “end Donald Trump’s presidency as we know it,” Newsom said. “It is all on the line, a bright line, in 2026.”

California’s Proposition 50 asked voters to suspend House maps drawn by an independent commission and replace them with rejiggered districts adopted by the Democratic-controlled Legislature. Those new districts would be in place for the 2026, 2028 and 2030 elections.

The recast districts aim to dilute Republican voters’ power, in one case by uniting rural, conservative-leaning parts of far northern California with Marin County, a famously liberal coastal stronghold across the Golden Gate Bridge from San Francisco.

The measure was spearheaded by Newsom, who threw the weight of his political operation behind it in a major test of his mettle ahead of a potential 2028 presidential campaign. Former President Barack Obama urged voters to pass it as well.

“Republicans want to steal enough seats in Congress to rig the next election and wield unchecked power for two more years,” Obama said in one ad. “You can stop Republicans in their tracks.”

Critics said two wrongs don’t make a right. They urged Californians to reject the measure, even if they have misgivings about Trump’s moves elsewhere.

Among the most prominent critics was Arnold Schwarzenegger, the movie star and former Republican governor who pushed for the creation of the independent commission, which voters approved in 2008 and 2010. It makes no sense to fight Trump by becoming him, Schwarzenegger said in September, arguing that the proposal would “take the power away from the people.”

After an early burst of TV advertising, opponents of the plan struggled to raise cash in a state with some of the nation’s most expensive media markets.

Total spending on broadcast and cable ads topped $100 million, with more than two-thirds of it coming from supporters. Newsom told people to stop donating in the race’s final weeks.