The electoral map in November was largely a sea of red, but there is a bright spot — or really, three — for Golden State Democrats.

In the Central Valley, the Antelope Valley and Orange County, a trio of Democratic congressional challengers unseated Republican incumbents as the party narrowed the GOP’s razor-thin majority in the House of Representatives.

The victories of Adam Gray, George Whitesides and Derek Tran — and a few Democratic House pickups elsewhere — were a silver lining for their party in a year that Republicans won both houses of Congress, Vice President Kamala Harris lost to Donald Trump in all seven swing states, and California voters backed away from progressive ballot measures and criminal justice reform favored by many Democrats.

“If you told me all that, I’d ask: How many seats did California Democrats lose?” said Paul Mitchell, a Democratic campaign consultant and vice president of Political Data Inc. “The petri dish was so inhospitable to Democratic gains, but Democrats still somehow still gained.”

In the aerospace-heavy Antelope Valley, Whitesides ran on his biography as a former NASA chief of staff and Virgin Galactic chief executive to oust GOP Rep. Mike Garcia.

In Orange County, Tran narrowly defeated Republican Rep. Michelle Steel to become the first Vietnamese American candidate to win the congressional district that includes Little Saigon.

And in the Central Valley, Gray — a moderate Democrat and longtime Modesto lawmaker — beat GOP Rep. John Duarte by a wafer-thin margin of 187 votes. The photo-finish race, called Tuesday, was the last in the country to be decided.

“These candidates told amazing stories about their districts and they were reflective of the districts they’re representing,” said Rep. Pete Aguilar (D-Redlands), the No. 3 Democrat in the House.

The candidates mostly talked about kitchen-table issues, he said, and also worked to show that the Republican incumbents had congressional voting records that were “out of step with their districts.”

The Orange County coast also delivered another key victory for Democrats, although not a flip. After Rep. Katie Porter chose not to run for reelection, Democrat Dave Min beat Republican Scott Baugh in the 47th Congressional District, keeping the seat blue.

All four victories were a vindication for California Democrats, who flipped seven House seats in the 2018 “blue wave,” only to lose four seats two years later and again in 2022.

“We knew from the onset how important these seats would be, and so did Republicans,” said Dan Gottlieb, a spokesperson for the Democratic Congressional Campaign Committee who worked on West Coast races.

He chalked up their victory to strong candidates with deep ties in their districts, weaknesses with the Republican incumbents and robust fundraising that allowed Democrats to “strain the GOP’s resources” and force them to play defense in more districts.

In the view of the Republican mayor of Newport Beach, however, despite Democrats’ gains, the party and its candidates didn’t spend enough time talking about crime and public safety. “That’s going to come back to bite Democrats really hard in two years, if that’s not a main focus,” Will O’Neill said at a panel at UC Irvine on Friday.

The swing-district candidates cast themselves as moderates who didn’t toe the party line. All four broke with party leaders in Sacramento to support Proposition 36, the criminal justice reform measure that passed with overwhelming support.

Democrats and their outside allies launched their candidates onto the airwaves early on in Southern California’s expensive advertising market — including, in Tran’s case, in Vietnamese-language media.

“We tried to project a message … that we were going to stay focused on kitchen-table issues of economic growth, local job growth, and bringing costs down, and that really resonated with people,” Whitesides said.

He said his fundraising haul of $10 million helped “bring to light my opponent’s record, which past campaigns didn’t have to the same extent.”

Republicans won California’s other two battleground House races by comfortable margins.

In the Central Valley, Rep. David Valadao cruised to reelection, beating Democrat Rudy Salas by a wider margin than two years ago as Kern County swung further right.

In Riverside County, voters reelected longtime GOP Rep. Ken Calvert over Democrat Will Rollins, a former federal prosecutor who raised nearly $12.5 million and sparked a wave of voter enthusiasm.

Rollins came 1 point closer than during his first run against Calvert in 2022. The 41st Congressional District supported Trump by a slim margin in 2020, but shifted nearly 5 points to the right this year.

In all, nine of California’s 58 counties flipped from supporting Biden in 2020 to Trump.

The Republican Party also picked up three seats in the state Legislature, flipping seats in Orange County, Riverside and the Inland Empire, suggesting Democrats in once-safe districts could see bigger fights in the future.

“There’s a massive shift right now in realignment of people willing to vote for a Republican, perhaps for the first time in their lives,” O’Neill said.

He said he would not be surprised if Republicans took back “a number of the seats” in 2026, including Tran’s, and said Min could have a tough path to reelection if Republicans choose the right candidate.

Aguilar said California’s rightward shift is proof that Democrats will need to work more to address, and talk more about, the economy, but a permanent rightward shift isn’t a foregone conclusion.

“They might have been Trump voters in November, but I don’t think these are Republican Party voters,” Aguilar said. “When they see unified control in Washington, and what a Donald Trump agenda looks like, I do think it will make them recoil.”

Particularly in the Central Valley’s 13th Congressional District, voters were saying “we want something different,” Gray said.

“When I went out and campaigned on my record of independence in Sacramento … and being unafraid to take on the political parties, either my own or the opposition, if I needed to — I think that’s what people voted for,” said Gray, a former member of the state Assembly.

Biden dropping out of the presidential race may also have moved the needle for Democratic candidates in some of the state’s most competitive House races — although Harris did not prove to be all that popular in her home state, either.

Although the state’s election data aren’t finalized, voter turnout fell in 2024 among Democrats and Harris received a lower share of the vote — 58.5% — than Barack Obama in 2012, Hillary Clinton in 2016 and Biden in 2020.

“We had an old-guy problem, and after the debate, we had a credibility problem,” said Orrin Evans, a consultant for the Min and Tran campaigns. “We fixed the old-guy problem, but the credibility problem remained.”

After the election, both parties launched massive efforts to hunt down every voter whose mail ballot was flagged for a technicality, such as a missing signature or a signature that did not match the voter’s information file.

Hundreds of volunteers and campaign staffers went door to door, sometimes returning to the same doorstep four or five times, to notify voters and walk them through how to correct the issues, a process known as “ballot curing.”

Republicans had 70 staff members working on the ballot-curing operation, finding and fixing more than 10 times as many ballots as they had in 2022, the party said. On the Democratic side, the campaign used hundreds of volunteers and paid canvassers, including some who drove from San Francisco and Los Angeles.

Pablo Rodriguez, who ran an independent expenditure committee that supported Gray, said his organization focused on turning out Latina voters and voters without a party preference in the 13th District, including following up during the ballot-curing process.

“It’s not anything complicated,” Rodriguez said. “The hard part is the labor-intensive part of finding folks and making sure they have a desire to have their vote counted, given that so much of the news has already told them: ‘The election is already over, this is already done.’”

Mitchell said state data showed that 1,310 registered Republicans fixed technical issues and had their flagged ballots counted, as did 2,186 Democrats — far more voters than the 187-vote margin of victory.

Times staff writer Hailey Branson-Potts contributed to this report.