RIVERSIDE, California — As Republicans in competitive races across the country recalibrate their relationship with President Donald Trump, two Orange County incumbents forced into the same district are staking their political survival on proving unwavering loyalty to the president.
The loser of the intraparty clash between Reps. Ken Calvert (R-CA) and Young Kim (R-CA) will likely become one of the Republican casualties of California voters’ passage of Proposition 50, a 2025 ballot measure backed by Gov. Gavin Newsom (D-CA) and state Democrats that aimed to further shrink GOP representation in an already deep-blue state. Democrats currently dominate California’s U.S. House delegation 43-9, and under district lines taking effect in the 2026 cycle, they could plausibly expand that advantage to 48 seats.
In Southern California, Kim and Calvert are headed for a political collision. The fight centers on the newly configured District 40, a sprawling region southeast of Los Angeles that stretches across Orange County suburbs, parts of Riverside County, and mountain communities along the Santa Ana range. Once considered competitive territory, the district was transformed into safe Republican ground after Democratic mapmakers packed it with conservative voters siphoned from neighboring GOP seats.
The redistricting reshuffle pulled much of Calvert’s former base from the 41st Congressional District into Kim’s 40th District, creating a rare incumbent-versus-incumbent showdown in territory both lawmakers now claim as their political home turf.
The race has turned personal and ugly, with each candidate questioning the other’s competence and mental sharpness.
Both candidates are also locked in a battle to prove who is more closely aligned with Trump and his political movement as he approaches the midpoint of his second term. Each has cast themselves as the true MAGA standard-bearer, while television ads blanketing the airwaves accuse the other of being insufficiently conservative, exaggerating ties to the president, and lacking genuine loyalty.
“Trump-traitor Young Kim. A liberal and a liar,” one of Calvert’s ads says.
Kim pushed back, arguing Calvert is trying to redefine her because he has little to run on after decades in office.
“You would think he would be running on his own record, but if you don’t have anything to show for it, you start early by attacking your opponent and smearing my record and my name,” she said. “I guess that’s what happens when you’re not proud of your own record.”
In another ad, Calvert calls Kim a RINO — Republican In Name Only — and claims she “threatened” Trump, before throwing to a sound bite of her saying, “I’ll whip his butt.” The clip is from a 2020 event where Kim praised Trump’s leadership but said she wouldn’t let her daughters date or marry someone like him.
Kim’s campaign launched some pretty brutal ads of their own, including one that called Calvert “swampy” and “sleazy,” and said he was “busted with a prostitute” in his car in the 1990s. Calvert, who was never charged with a crime, admitted to having sex with the person because he was feeling “intensely lonely.”
“Screwing us, servicing himself, sabotaging Trump,” the voice in the 30-second ad said. “Ken Calvert, what a sleazebag.”
Calvert, 72, is the longest-serving Republican in California’s congressional delegation. He has spent 33 years in Congress, survived two rounds of redistricting, and says he is not intimidated by another political fight, especially against Kim.
“I was born there, I was raised there, and I started a business there,” he told the Washington Examiner. “I’ve lived there my entire life, and I’ve represented a majority of the people there.”
He also insists he is the candidate most similar to Trump.
“I’m the only real, true Trump conservative,” he said. “I’ve been endorsed twice by the president. I work with him, and not only that, I’ve done more in bringing federal dollars back to California than any member of Congress, I think, in history.”
Calvert, chairman of the House Appropriations Committee’s defense subcommittee, has secured billions of dollars for defense and water infrastructure projects, including the Santa Ana River Mainstem Project, which provides flood protection across Riverside, San Bernardino, and Orange counties.
But Kim, 63, has made clear she has no intention of leaving Congress after nearly six years in office. Backed by strong fundraising, she argues it is time for Calvert’s decadeslong tenure to end.
“How many more decades does he need to get things done?” Kim told the Washington Examiner. “The reality is that Calvert has had enough time to prove himself, and after 30 years, he simply has not.”
Kim, who serves on the House Financial Services Committee, argues longevity alone is not an accomplishment and points to her own legislative record: more than 180 bills passed by the House and more than 50 signed into law.
“This is only my third term, and it didn’t take me 30 years to get things done,” she said.
California political analyst Jamie E. Wright told the Washington Examiner it is not surprising the two incumbents have sharpened their attacks.
“When two incumbents run against each other from the same ideological position, they must find ways to differentiate themselves,” she said. “This often involves challenging the opponent’s effectiveness, loyalty, endurance, electability, or authenticity. Don’t expect much debate over the broader conservative platform. Expect a debate over who is best positioned to keep the seat in Republican hands.”
Jeff Le, managing principal at 100 Mile Strategies and a former deputy Cabinet secretary to two-time Democratic Gov. Jerry Brown, called the matchup “one of the most intriguing congressional primaries in the country.”
“While their congressional records reveal a streak of bipartisanship and policy substance, their campaigns have focused heavily on aligning themselves more closely with the president’s views on immigration and the rhetoric associated with the current commander in chief,” he told the Washington Examiner. “Despite the president’s weak numbers statewide, his approval rating remains strong among the Republican base, even in blue California.”
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While the race has largely revolved around Kim and Calvert, they are not the only ones on the ballot. Six other candidates — five Democrats and one independent — are also competing in the primary.
California’s jungle primary system advances the top two vote-getters to the general election regardless of party affiliation, raising the very real possibility that Kim and Calvert could face each other again in November. If that happens, voters in District 40 are likely in for an even more bruising and expensive race.