Four House incumbents have already lost re-election bids so far this year, just a few months into primary season, and about a dozen more are facing legitimate threats in the coming months.
Two Republican incumbents are squaring off for one district in California next week, the latest example of redistricting changing not just general elections but primaries as well, after two Democratic members lost in Texas last week. But the heaviest upcoming primary action will be on the Democratic side, where a handful of incumbents in California face energetic challengers arguing that voters want a fresh face.
What the Left Is Saying
Progressive challengers and their supporters argue that generational change is essential for the Democratic Party to remain competitive and responsive to voters. In Connecticut, former Hartford Mayor Luke Bronin is challenging Rep. John Larson, a 28-year incumbent who served in House Democratic leadership. Bronin has outraised Larson and won the state Democratic Party endorsement at its convention.
Bronin said his campaign reflects broader voter desires for new representation. "Congressional seats were not meant to be lifetime appointments and the Democratic Party would be so much stronger if we had more people who recognize that part of leadership is knowing when it's time to pass the torch," he told NBC News.
In California, challengers are targeting multiple longtime incumbents including Reps. Mike Thompson, Doris Matsui, Brad Sherman, Jimmy Gomez and Linda Sánchez in the state's top-two all-party primaries. Entrepreneur Eric Jones has contributed more than $5 million of his own money to challenge Thompson, while former White House policy aide Jake Levine loaned his campaign $500,000 and narrowly outraised Sherman.
Mai Vang, a Sacramento City Council member challenging Matsui, represents the generational shift argument directly. The challengers argue that voters are looking for representatives who will bring new perspectives to Congress rather than career politicians who have spent decades in office.
What the Right Is Saying
Conservative critics say the Democratic Party's internal upheaval reveals deeper structural problems as it attempts to retake control of Congress following the 2024 presidential election. Some Republicans argue that these primary battles could weaken Democratic nominees heading into general elections, giving GOP candidates an advantage in competitive districts.
Incumbent members themselves are pushing back against the notion that experience is a liability. Larson defended his record and influence, arguing that seniority on key committees like House Ways and Means provides tangible benefits for constituents. "I don't know what Luke stands for, other than I'm old," Larson said on a press call with allies from the Working Families Party.
Some Democratic incumbents are taking aggressive steps to protect their seats. Matsui's campaign website has included messages asking outside groups to boost Republican candidates in an apparent strategy to help block progressive Democrats from advancing to general election matchups under California's top-two system, which can pit two Democrats against each other in November regardless of primary outcomes.
Republicans note that while incumbency advantages remain historically significant, the current environment appears more favorable than usual for challengers. The party out of power often benefits from voter dissatisfaction with the majority, and these internal Democratic battles suggest broader anti-establishment sentiment is affecting both parties.
What the Numbers Show
Incumbent members of Congress are traditionally difficult to defeat in primaries, but 2026 is showing unusual activity. Four incumbents have already lost their re-election bids this year, a notable number for this early in primary season. About a dozen more face credible challenges heading into upcoming elections.
In California specifically, five Democratic incumbents face well-funded challengers in the state's top-two all-party primaries: Thompson, Matsui, Sherman, Gomez and Sánchez. The Financial Disclosure Act filings show Jones contributed over $5 million to his own campaign against Thompson, while Levine loaned his campaign $500,000 to challenge Sherman.
The Connecticut race shows Bronin outraising Larson, though final pre-primary finance reports will provide more complete pictures of each campaign's financial position. Hawaii Rep. Ed Case faces a primary challenge as one of the state's longest-serving members, and similar generational dynamics are playing out in races involving Democratic Reps. Stephen Lynch in Massachusetts, Diana DeGette in Colorado, Shri Thanedar in Michigan and Adriano Espaillat in New York.
The Bottom Line
The 2026 primary season is producing an unusual number of serious challenges to sitting House members, with Democrats experiencing the most visible upheaval. These races represent more than individual contests; they reflect broader debates within the party about generational representation, ideological direction and what qualities voters value in their representatives.
For now, incumbents retain structural advantages including name recognition, established donor networks and institutional support from party organizations. But the level of primary competition suggests some electorates are willing to consider alternatives more seriously than in previous election cycles. The outcome of these races will help determine whether 2026 represents a temporary spike in anti-incumbent sentiment or the beginning of a sustained shift in how House seats change hands.
Voters in California cast ballots Tuesday, with results from those top-two primaries expected to indicate which incumbents face genuine danger and which challenges have failed to gain traction. Similar contests in Connecticut, Massachusetts and Hawaii will follow in coming weeks.