California’s Proposition 50 is a direct response to the Texas legislature creating five more safely Republican or GOP-leaning seats to help protect President Donald Trump’s party from losing the House majority next year. The Trump White House has pushed for GOP-favorable House remaps in several other states, too.

In California, though, Proposition 50’s passage is set to make its House districts a much deeper shade of blue.

“In past elections for Congress, a lot of times, a district would vote for the Democratic candidate, and for Trump,” said Fabian Valdez, a data analysis guru in Long Beach, California, with extensive experience consulting on redistricting.

But chances of such split-ticket voting are thinner now, with the new lines taking effect after the 2026 midterm elections, Valdez said in an interview.

Democrats haven’t been shy about naming their political targets: Reps. Ken Calvert (R-CA), Darrell Issa (R-CA), Kevin Kiley (R-CA), Doug LaMalfa (R-CA), and David Valadao (R-CA). The passage of Proposition 50 means each will see their current House districts redrawn to various degrees, adding in blue precincts and chopping off reliably GOP-voting precincts.

Still, House Republicans in California have some reason for solace in Democrats’ efforts to change the state’s delegation from a wide 43 to 9 over Republicans, to an overwhelming 48 to 4. The new map will leave a few House Republican survivors in districts already varying shades of red.

“In each of those past four elections, a Republican won four out of four times” in those districts, Valdez said, citing his analysis of how the districts would have voted in congressional races from 2018 to 2024.

The incoming maps will make more red the current districts of Reps. Vince Fong (R-CA), Tom McClintock (R-CA), and Jay Obernolte (R-CA). The Southern California district of Rep. Young Kim (R-CA) also becomes more Republican, but she could face competition for the seat from current House GOP colleagues.

That’s because under the new congressional map configurations, some of the five House Republican lawmakers getting turfed out could run in a different district. Even if that means challenging an incumbent in California’s June 2026 all-party primary (more on that below). So, two or more House incumbents could end up facing off in the November 2026 general election.

In the wake of the new House maps being adopted, ambitious politicians on both sides of the aisle are recalibrating their political plans. These are the red puddles in a sea of blue that will emerge when new House districts take effect on Jan. 3, 2027, when the 120th Congress opens.

Kevin McCarthy’s old district gets even more red

Vince Fong already holds California’s reddest House seat. It will lean even further in the Republicans’ way under the new map.

Fong won a May 2024 special election for California’s 20th Congressional District, covering the eastern Central Valley from the Bakersfield to Fresno areas. The new House maps don’t significantly change its geographic contours. In 2024, Trump beat Democratic rival Kamala Harris there 64% to 34%. The new version would shift 1.4 points to the right, per a recent Los Angeles Times analysis, using results from the 2024 presidential election to calculate the margin of victory between Democrats and Republicans in the redrawn districts.

Fong succeeded former House Speaker Kevin McCarthy in the district. McCarthy quit Congress when Republican House colleagues ousted him from the chamber’s top job in October 2023, after only nine months. Fong, then a state Assemblyman representing a similar political turf, easily won the open seat.

Veteran lawmaker’s district largely intact

To the north and east, far away from liberal coastal California, Tom McClintock also should be in good shape to hold a tweaked version of his district’s current version, covering the Central Valley and Sierra Nevada foothills.

Party registration in the new 5th Congressional District will be 44% Republican to 29% Democratic. That makes sense, as it will stretch hundreds of miles along the Nevada state line and west into California’s agricultural heartland. Like McCarthy’s old district, this has long been conservative territory.

“Much of the Central Valley and North State is dominated by agriculture, and many of the farmers have felt that Republican ideas speak to them,” said Kerida Plaza, a PhD candidate at the University of Rochester, where she plans to write her dissertation about the history of Republicans in California between 1970 and 2016.

“Every time a Republican candidate wears cowboy boots and plaid in a direct-mail piece, they are speaking to the sensibilities of rural farmers,” added Plaza in an email interview.

McClintock, first elected to the House in 2008, will have the distinction of having represented another huge swath of California. He was a state assemblyman from 1982 to 1992, then again from 1996 to 2000. And then a state senator from 2000 to 2008. McClintock’s long stints in California’s capital of Sacramento were interspersed with several unsuccessful runs for statewide office.

Back then, McClintock, 69, represented state legislative districts based in and around Thousand Oaks, a suburban Ventura County community just north of the Los Angeles County line. When a House seat in the Sierra foothills opened up in the 2008 election cycle, McClintock shifted north, successfully running for office there, and has been ensconced in California’s northeastern and central realms ever since.

Congress’s AI specialist set to keep his seat

Jay Obernolte will see his current district, covering the Mojave Desert region of San Bernardino County, stay largely the same, but with some new territory on its eastern flank. The district, taking in fast-growing Los Angeles exurbs where costs of living are (for now) lower, won’t just extend to California’s state line with Nevada, as is currently the case, but also Arizona.

“It’s like 85% his old district,” said Valdez, per his Proposition 50 redistricting analysis.

And it will grow more Republican. GOP registration in Obernolte’s new district is 38% to 32% for Democrats. Yet, that only tells part of the political story, since in the 2024 presidential election, Trump would have beaten Democratic rival then-Vice President Kamala Harris there 58% to 39%.

Obernolte stands out in Congress for his engineering background, with an emphasis on artificial intelligence before it went mainstream. The former high school valedictorian in 1992 obtained his Bachelor of Science degree in engineering and applied science from the California Institute of Technology. In 1997, he earned his Master of Science in artificial intelligence from UCLA. Branching out academically, Obernolte, in 2020, finishing up six years in the state Assembly, earned a Doctorate in Public Administration from California Baptist University in Riverside.

Obernolte is the only former video game developer in Congress. With the rapid growth of AI in recent years affecting virtually all walks of life, Obernolte has become an unofficial and bipartisan tutor to less tech-savvy House colleagues on the technology. As chairman of a bipartisan House AI task force in 2024, Obernolte helped craft a comprehensive road map for how Congress can respond to the tech that’s triggered fear and excitement globally.

Orange County GOP vote sink

The biggest open question surrounding House Republicans and California’s rejiggered House maps concerns Young Kim. The former congressional aide and state assemblywoman won an Orange County-based House seat in 2020. Her current district covers eastern Orange County and some surrounding communities.

In the new 40th Congressional District, Republicans have a voting registration edge over Democrats 40% to 31%. That’s effectively a “vote sink,” redistricting parlance for the majority party (in this case, the Democrats) conceding a district to the opposition to make bigger gains elsewhere.

The new district is a throwback of sorts to Orange County’s mid- to late-20th-century role as a bastion of conservative Republicanism. Presidents Richard Nixon and Ronald Reagan, former statewide officeholders in California, ran up some of their top White House race margins in Orange County.

“During and after World War II, many people moved to the Sunbelt, which includes Orange County, and these people were often conservative leaning,” said Plaza, the PhD candidate.

“Sunbelt conservatives often worked with and were influenced by conservatives in other parts of the West and the South to push back against the eastern wing of the party,” said Plaza, now in western New York after Sacramento experience as a top aide to now-Rep. Kevin Kiley during much of his six-year state Assembly career. “Typified by characters such as Nelson Rockefeller, the eastern wing of the party was known to be more moderate.”

The 40th Congressional District lines will shift somewhat, and Kim, 63, would seem in a strong political position to slide into it. However, with other House Republicans seeing their current districts torn out from under them, one is running for the newly created seat, and another still might.

Rep. Calvert said on Nov. 5 that he is running for the 40th Congressional District seat. He was first elected to the House in 1992, and now represents an inland district stretching from the southern Riverside suburbs to Palm Springs. Calvert, 72, over the past two election cycles, ran in more politically competitive turf than much of his congressional career, the result of redrawn seats by California’s independent redistricting commission (which, under Proposition 50, will be suspended for the 2026, 2028, and 2030 election cycles).

In a Republican-majority House, Calvert has significant influence as chairman of the Defense Appropriations Subcommittee, which oversees Pentagon spending. Yet, that’s all threatened by the Proposition 50 maps, which completely dismantle his current district, parceling many of the most Republican-leaning areas into surrounding Democratic majority seats.

So, Calvert’s best political option for continuing his House career is to run in CA40, against Rep. Kim, even though it’s not his traditional home base. The district might also be tempting for Darrell Issa, who now represents a district covering southern Riverside County and inland San Diego County.

Issa, 72, won the 48th Congressional District in 2024 with nearly 60% of the vote in the suburban and rural region. But redistricting will pour tens of thousands of new voters in from bluer areas, including Palm Springs, Vista, and San Marcos, while removing some redder areas such as Santee and Lakeside.

Issa could have an incentive to stay put and seek reelection in the district, despite its more unfavorable shape. In the 2024 presidential race, Harris would have beaten Trump by a relatively slim margin of 50.26% to 47.14%.

“The reality is [District] 48 is winnable by Issa,” said Valdez, the redistricting data analyst. “It’s not like it’s a slam dunk for any Democrat running for that district.”

TRUMP BLASTS EARLY AND MAIL-IN VOTING, COMPLICATING CALIFORNIA GOP VOTER PUSH

Issa’s biggest advantage if he moved north to run in the new 40th District is money. As in, he has lots of it, as one of the richest members of Congress. The car alarm magnate has not been shy about funding his prior campaigns and could, in theory, do it again in the Orange County-based congressional district.

It’s an open question whether three House Republicans will run against each other for the same House seat. But with the extent of the political musical chairs forced by Proposition 50 now coming into focus, nothing can be ruled out.