Democrats are sweeping California's Central Valley in the nation's last major House race

Democrats sought the last congressional seat of the 2024 election cycle on Tuesday as Merced Democrat Adam Gray ousted incumbent Republican John Duarte in a runoff race in California's Central Valley.

California's 13th Congressional District was the last major race for the US House of Representatives, and had the closest margin in the country. Gray was leading by 187 votes when Duarte conceded Tuesday evening.

After trailing in the first three weeks of counting, Gray took the lead on November 26 as mail-in ballots tilted in his favor.

Gray, 47, said in a prepared statement Tuesday that he was honored to be nominated and thanked the volunteers, voters, donors, campaign workers and family members who helped him succeed.

“This district is ready for an independent and responsive leadership that always puts the people of the Valley ahead of partisan politics,” said Gray.

Gray said he would work to build a bilateral relationship and bring “clean water, better educational opportunities, strong infrastructure and good-paying jobs.”

Duarte agreed Tuesday night, a campaign spokesperson said.

“How's that going,” Duarte told the Turlock Journal on Tuesday. “I am a member of the legislature, and I did not plan to be in Congress forever. But whenever I think I can make a difference, I will look to serve the public in different ways, including running for Congress again.”

Republicans will retain a slim majority in the House of Representatives next year. With Gray's victory, Republicans will hold 220 seats – slightly more than the 218-seat limit needed to control the chamber – and Democrats will hold 215.

The GOP will have a very slim majority in parts of January. Rep. Matt Gaetz (R-Fla.) resigned last month. Attorney Michael Waltz of Florida has been appointed as President-elect Donald Trump's national security adviser and is expected to step down, as is Rep. Elise Stefanik from New York if confirmed as a United Nations ambassador.

The 13th Congressional District was one of twelve seats in California seen as important in the fight for control of Congress, and it was one of three in the state where Democrats came out of Republican control.

In Orange County, Democrat Derek Tran ousted Republican Rep. Michelle Steel, and in northern Los Angeles County, Democrat George Whitesides defeated Republican representative Mike Garcia. The Democrats also held on to the seat left by Rep. Katie Porter (D-Irvine), and Sen. State Dave Min defeated Republican Scott Baugh.

Republicans fared better in another Central Valley district, where Rep. David Valadao defeated Democrat Rudy Salas by nearly 7 points. Salas on Tuesday filed to run for Congress again in 2026.

The GOP also held a seat in Riverside County, where voters re-elected Republican Rep. Ken Calvert replaced Democrat Will Rollins, a former federal prosecutor.

Read more: In California's 'purple' state, the GOP congressman is fighting to defend the seat he won by 564 votes.

The rural 13th Congressional District stretches from Coalinga to Modesto, covering Merced County and parts of Fresno, Madera, San Joaquin and Stanislaus counties.

The district appears green on paper, with 42% of registered voters affiliated with the Democratic Party, compared to 29% registered Republicans and 22% registered with no party preference.

But the Central Valley is more purple than the bluer states around the Bay Area and Los Angeles, and conservative Democrats in the area tend to cross party lines to vote for Republicans.

The 2024 campaign was a repeat of 2022, when Duarte defeated Gray by 564 votes, the second closest in the country.

This year, Duarte campaigned on lowering gas prices and the cost of living. Duarte, whose family owns a large ranch in the San Joaquin Valley, pitched to voters as a moderate Republican, saying he had pushed his party on abortion and immigration, instead sticking to middle-of-the-road policy proposals.

Gray styled himself as “a senior executive,” pointing to his decade in the Legislature as proof that he can work across party lines. In August, he told The Times that he chose to run against Duarte again because he thinks incumbents and Republicans have done little in Congress to help everyday Americans.

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This story first appeared in the Los Angeles Times.