A wave of resignations, retirements, and even an expulsion placed a large number of seats up for grabs, and primary contestants are rushing to claim them.
All 435 seats in the House of Representatives and one-third in the Senate are open for voters in each election cycle. This year, the number of seats that won’t be contested by incumbents will add to some interesting primary contests.
Primary races often signal the stakes for the general election and can forecast the winner in a state or district where one party dominates.
Here are 10 primary races to track that could shift the momentum in either chamber.
West Virginia US Senate Seat
Sen. Joe Manchin (D-W.Va.) isn’t seeking reelection, leaving his Senate seat ripe for flipping in this solidly red state.
The top Republican primary contenders are former West Virginia Gov. Jim Justice and Rep. Alex Mooney (R-W.Va.).
Mr. Justice has raised $1.5 million and garnered endorsements from former President Donald Trump, Senate Minority Leader Mitch McConnell (R-Ky.), and the National Republican Senatorial Committee.
Mr. Mooney has raised $2.3 million and gained endorsements from Sens. Ted Cruz (R-Texas) and Paul Rand (R-Ky.) and Rep. Jim Jordan (R-Ohio).
Marine Corps veteran Zachary Shrewsbury is the only candidate in the Democratic primary race to date.
Cook Political Report rates this seat as “solid Republican.” The primary election is scheduled for May 14.
Montana US Senate Seat
Sen. Jon Tester (D-Mont.) is the only statewide elected official who’s a Democrat. As such, the third-term incumbent is always considered vulnerable to a Republican challenge.
Mr. Tester has never won 50 percent or more of the vote in this state where Libertarian candidates usually claim up to 7 percent of the total.
The primary battle will happen on the Republican side and will determine the stakes for the general election.
Tim Sheehy, a former Navy SEAL and CEO of Bridger Aerospace, is the most serious contender to date, having the backing of national party leaders.
Former state Attorney General Brad Johnson is also in the race, and Rep. Matt Rosendale (R-Mont.) has hinted for several weeks that he intends to make another bid for the seat. Mr. Rosendale is a hardliner who was one of eight Republicans who voted to oust Rep. Kevin McCarthy (R-Calif.) from the House speakership in October 2023.