Thomas Massie

More than a dozen states are set to hold US House primaries in the next five weeks.

Some will set up key general election matchups that could determine control of the US House in November. Others will reveal something about the dynamics that are shaping the two parties and what it means to be electable.

President Donald Trump’s political power will be put to a high-profile test in Kentucky, where he’s targeted Rep. Thomas Massie, and a crowded primary in Montana. And Democrats are facing off in crowded primaries in Pennsylvania, Nebraska and California, with opposing visions of the party’s future and who is most likely to flip Republican-held districts.

Here are six upcoming primary elections to watch.

May 5: Ohio’s 9th District

Democratic Rep. Marcy Kaptur beat Republican former state Rep. Derek Merrin by just under 2,400 votes in 2024. Two years later, Merrin is running in a crowded primary against four other Republicans in his bid for a rematch.

Merrin has pointed to his previous close finish, but other candidates have called for a fresh face. Merrin faces Air Force veteran Alea Nadeem, healthcare executive Anthony Campbell, state Rep. Josh Williams, and former Immigration and Customs Enforcement Deputy Director Madison Sheahan.

Republicans see this as a key pickup opportunity. Whoever wins the primary this May will be running on a more favorable map for Republicans following last year’s Ohio redistricting — though they’ll also face a Libertarian Party candidate as well. Two years ago, a Libertarian candidate won more than 15,000 votes, likely boosting Kaptur.

But Kaptur, who has represented the Toledo area since 1983, can’t be underestimated. She won her 2024 reelection bid even as Trump carried the district by nearly 7 points.

May 12: Nebraska’s 2nd District

Democrats are optimistic about winning back this seat now that five-term Rep. Don Bacon is retiring. Bacon was one of three Republicans in 2024 to win a district that went for former Vice President Kamala Harris over Trump, according to the University of Virginia’s Center for Politics.

Brinker Harding, an Omaha city councilman endorsed by Trump, has locked up the Republican nomination. Democrats, meanwhile, are wading through a crowded primary. Two candidates — former corporate executive Denise Powell and state Sen. John Cavanaugh — have led the field in fundraising and high-profile endorsements.

Powell’s allies, including EMILY’s List, which boosts Democratic women running for office who support abortion rights, have argued that if Cavanaugh is elected, the state’s Republican governor would be able to choose his replacement in the state Senate, potentially giving the state GOP an extra vote to change the way Nebraska awards Electoral College votes in presidential elections.

Nebraska and Maine are the only two states that award Electoral College votes by congressional district. Some Republicans in Nebraska have called for changing to a winner-take-all approach and eliminating the state’s “Blue Dot” in the 2nd District.

Reflecting the importance of that question, Cavanaugh has a section of his campaign website devoted to the Blue Dot. He argues that Nebraska Democrats are optimistic they will gain seats in the legislature in November, weakening Republicans’ ability to eliminate the standalone Electoral College district.

American Action Network, which describes itself as a center-right think tank, is airing ads saying Cavanaugh is “working to enact Trump’s policy right here in Nebraska.” That’s spurred talk that Trump allies are trying to undercut Cavanaugh with Democrats ahead of the primary.

“These dark money super PACs are just spreading MAGA Republican talking points,” state Sen. George Dungan says in one recent Cavanaugh ad.

May 19: Kentucky’s 4th District

This primary in a solidly Republican district isn’t about House control, but about the president’s control of his party.

Massie, the seven-term congressman and frequent thorn in Trump’s side, is running against former Navy SEAL Ed Gallrein, who has the president’s endorsement.

Massie has frequently broken with Trump during the president’s second term and voted against the wishes of House Republican leadership. Those “no” votes — on spending bills and last year’s One Big Beautiful Bill Act —have held more weight as Republicans navigate a razor-thin majority. Massie also led a push to force a House vote on legislation requiring the Department of Justice to release its records on Jeffrey Epstein.

The president has also targeted Massie’s wife, saying the lawmaker has become a liberal because his spouse is supposedly “a Radical Left ‘flamethrower.’” Massie later brought her to the State of the Union address as his guest.

“So now he’s attacking my wife who voted for him three times,” Massie wrote on X. “Maybe someone told him she’s actually the one who suggested I ask Pam Bondi in person at a dinner when we would get Phase 2 of the Epstein files. Bondi said there were no more files. As they say, the rest is history.”

May 19: Pennsylvania’s 7th District

Four Democrats are vying for the chance to take on Republican Rep. Ryan Mackenzie in this toss-up district.

Bob Brooks, the president of the state firefighters’ union, has picked up endorsements from across the ideological spectrum, including Gov. Josh Shapiro and independent Vermont Sen. Bernie Sanders. He’s running on a populist message and touting his experiences with financial hardship as evidence that he understands the issues that matter to working-class voters.

His opponents — former federal prosecutor Ryan Crosswell, former nonprofit executive Carol Obando-Derstine and former Northampton County Executive Lamont McClure — have started pouncing on negative stories about the perceived front-runner.

After the Washington Post reported on Brooks’ history of posting right-wing social media memes, including a post defending gun ownership following a deadly 2019 shooting in El Paso, Texas, Crosswell’s campaign manager, Nick Mattes, compared Brooks to Sen. John Fetterman, who has angered liberals by breaking with his fellow Democrats and praising Trump at times.

“Pennsylvania voters aren’t gonna be fooled again,” Mattes told the Post.

Brooks apologized in a statement to CNN for some of the posts and asked voters to look at his record of service to the community. He also said he was a lifelong Democrat — a dig at Crosswell, who spent most of his adult life as a registered Republican.

June 2: Montana’s 1st District

Rep. Ryan Zinke announced in early March that he would not seek reelection, setting up two competitive primaries for this western Montana seat.

This is the sort of Republican-leaning seat that Democrats believe they can win in a strong year with the right candidate. Zinke beat the Democrats’ 2024 nominee by nearly 8 points.

On the Democratic side, most of the attention has gone to Sam Forstag, a Sanders-endorsed former smokejumper and union leader who represents the party’s efforts to appeal to working-class voters with populist candidates. But he’s been outraised so far by Ryan Busse, a former gun company executive who now criticizes the industry. Matt Rains, an Army veteran and rancher, and Russell Cleveland, a Navy veteran, are also contesting the nomination.

On the Republican side, there is a competitive and at-times contentious primary. Aaron Flint, an Army National Guard veteran, entered the race in March with endorsements from Zinke, GOP Sen. Tim Sheehy and, soon after, Trump. The House Republicans’ campaign arm named Flint to its “MAGA Majority” list for the fall.

His rivals include Al Olszewski, a doctor and former state senator who narrowly lost to Zinke in 2022. Last month, Zinke laid into Olszewski in an opinion piece published by the Daily Inter Lake, accusing him of having spent “the better part of a decade lying to Montana, dividing conservatives,” and using his position as a county GOP chairman to “pull good candidates down.”

Olszewski described the attacks from Zinke as a “desperate attempt to knock my strong campaign off track” in a statement to CNN.

“This election really comes down to this: does Washington D.C. choose Montana’s congressman or do the People of Montana?” Olszewski said. “I believe it is the People of Montana, and I will continue to earn their support by focusing on issue-based messaging about the future of our great state.”

June 2: California’s 22nd District

California Democrats’ successful redistricting effort has scrambled the math for Republicans in several of the state’s congressional districts.

In California’s 40th District, incumbent Reps. Young Kim and Ken Calvert are battling for reelection after being drawn into the same district. In the 45th District, a contentious Republican field is vying to take on freshman Democratic Rep. Derek Tran in a seat that’s now more favorable for him.

But in the state’s Central Valley, Rep. David Valadao will still be a formidable opponent for whichever Democrat pulls ahead in the June 2 primary.

The two Democrats — state Assemblymember and physician Jasmeet Bains and school board trustee and activist Randy Villegas — represent different wings of the party.

Bains, who is backed by EMILY’s List, has run as a moderate, while Villegas has run as a progressive. Villegas has criticized her for voting against advancing last year’s Democrat-led gerrymander and for accepting money from corporations. But some Democrats see her willingness to buck the party as an asset in a general election matchup against Valadao.