Rep. Katie Porter of Irvine, a rising star in the Democratic Party, fended off a challenge from Republican Scott Baugh, a former state lawmaker, to secure her third term in Congress.

The race was called Thursday by the Associated Press, though official results will take longer.

Control of the House tipped to Republicans on Wednesday with Rep. Mike Garcia’s win in northern L.A. County; now California’s remaining uncalled congressional races will determine the size of the GOP’s majority.

Although the California congressional delegation looks largely unchanged, several races were decisive in the GOP’s successful effort to seize House control. Porter’s and Garcia’s districts were among five in California that had been labeled toss-ups by the nonpartisan Cook Political Report, which has rated House and Senate races for decades.

An additional six districts in the state were deemed competitive.

There have been no upsets so far; the Associated Press has called eight of the competitive races, split evenly between the parties, with the incumbents winning in each contest.

Porter thanked volunteers and supporters for her win and said on Twitter: “Families can count on me to continue standing up for them, speaking truth to power, and fighting corporate abuse.”

The battle for the 47th Congressional District stayed relatively under the radar for most of the election cycle, but emerged in recent weeks as a fiercely fought campaign, as Republicans appeared to build momentum in a number of California congressional races.

Porter, 48, was swept into Congress in 2018 as part of that year’s blue wave and quickly built a profile that extended beyond Orange County.

Her appearances at congressional hearings, wielding a white board and lobbing tough questions at corporate executives and Trump administration officials, repeatedly went viral. Her national notoriety became a fundraising juggernaut; she was one of the top House fundraisers this election cycle.

Porter’s success on the national stage, however, belied the challenging terrain back home in Orange County. Democrats swept four congressional races in the longtime conservative stronghold in 2018 and surpassed Republicans in the county’s voter registration a year later.

But the GOP won back two congressional seats in 2020 even as Joe Biden won handily there, a sign that a substantial number of voters were rejecting former President Trump, not the Republican Party writ large.

Redistricting posed additional challenges for Porter. Two-thirds of voters in the district had never seen her on a ballot before, and the boundaries included conservative enclaves such as Huntington Beach and Newport Beach, in addition to more liberal Irvine, where Porter lives.

Baugh, 60, ran a campaign that evoked the pre-Trump version of his party. The former county GOP leader made a fiscally conservative pitch that hammered his opponent on inflation and crime. Porter attacked Baugh’s opposition to abortion rights and touted Democrats’ work to address prescription drug costs. Baugh’s campaign did not respond to a request for comment.

“I am very proud of the campaign we waged on the issues that matter to the American people,” Baugh said Thursday in a statement. “In the end we could not overcome the overwhelming financial advantage that Porter had in this race, but we came awfully close.”

Four California congressional races remain undecided.

In the Central Valley, GOP Rep. David Valadao is facing a challenge from Democratic Assemblymember Rudy Salas, who would be the first Latino sent to Congress from that area. An open seat in the Central Valley was also too close to call, as was one in a sprawling district along much of the state’s eastern border, from Death Valley well past Lake Tahoe. Another race, between two Democrats, is playing out in an L.A. district that includes downtown, Koreatown, Eagle Rock and Boyle Heights.

In addition to Porter’s race, seven other competitive races were called by the AP, prior to Thursday. They were won by:

Republican Rep. Mike Garcia: Garcia’s reelection dashed Democrats’ hopes that they could reclaim a district where they held a significant registration advantage. The Republican defeated Christy Smith, a Democratic former state lawmaker whom he had defeated twice before: in a 2020 special election race and again later that year, when he won by 333 votes.

Democratic Rep. Mike Levin: Democrats were so concerned about this coastal district that straddles Orange and San Diego counties that President Biden made a last-minute appearance with Levin days before the election.

But the incumbent and former environmental attorney bested Republican Brian Maryott, a former Wells Fargo executive, in the district that includes Marine Corps Base Camp Pendleton and a mothballed nuclear power plant.

Democratic Rep. Josh Harder: Harder won election a Stockton-centered congressional district, beating Republican Tom Patti, a San Joaquin County supervisor and businessman. Harder, who represents a neighboring district, stressed his independence from his party in the Central Valley race. Both candidates tried to paint their rivals as beholden to the extremes of their respective parties, but their behavior and messaging often reflected the moderate views of many of the region’s voters.

Republican Rep. Michelle Steel: Steel held on to her congressional seat after a campaign that included claims of red-baiting, misogyny and racism in a congressional district created to empower Asian American voters. In an Orange County district centered on the community of Little Saigon, Steel bested Democrat Jay Chen, a community college trustee and Navy reserve officer, in one of the most divisive races in California this year.

Steel used inflammatory and heavily doctored mailers and videos to try to paint Chen as a communist sympathizer because of a school board vote he made more than a decade ago in support of a Chinese cultural and language program. She faced pushback from Asian American groups, veterans and Chen, who is Taiwanese American and noted that he holds a security clearance and has family that fled communist China. The race was called on Monday, and Thursday night, as the remaining votes were being tallied, Steel led by more than seven percentage points.

Republican Rep. Ken Calvert: Calvert, the longest serving member of California’s Republican congressional delegation, narrowly beat back a challenge from Democrat Will Rollins, a former federal prosecutor who seized upon Calvert’s votes to overturn some results in the 2020 presidential election.

The Riverside Republican also had the challenge of trying to appeal to constituents added in redistricting — particularly those in Palm Springs, one of the nation’s largest concentration of LGBTQ voters.

Calvert’s past record included votes against gay rights and inflammatory attacks on a political rival who had been outed by a Calvert ally. But the Republican said his views had evolved, and he voted in support of same-sex marriage this year.

Democratic Rep. Julia Brownley: President Biden won this Ventura County-centered district by 20 points in 2020, so when Rep. Julia Brownley started sounding alarms in the lead-up to the midterm election, it sparked concern among Democrats.

But she comfortably beat Republican Matt Jacobs, a former federal prosecutor. Jacobs positioned himself as a moderate and focused on the economy. But he supported the Supreme Court’s decision to overturn Roe vs. Wade earlier this year and declined to disclose his personal views on abortion, issues that were seized upon by Democrats.

Republican Rep. Young Kim: Kim, who in 2020 was one of the first Korean American women to be elected to Congress, fended off a challenge from Dr. Asif Mahmood, a Democrat, to secure a second term.

Democrats had listed the affluent, suburban, mostly Orange County district as a target for flipping, despite Republicans’ more than 4-percentage-point voter registration advantage. However, the campaigns largely flew under the radar in recent months, outshined by competitive races in other Orange County districts.

Times staff writer Hannah Fry contributed to this report.