Just one House member has lost their primary so far this year — Rep. Jerry Carl in Alabama's 1st District — but Spartz could join that unfortunate group tonight. As Geoffrey mentioned, Spartz dug herself into a bit of a hole by announcing last year she would not seek reelection; she only recently changed her mind and didn't begin advertising on TV until early April.

Spartz isn't the only member in primary trouble; a number of Republicans and Democrats alike are facing challenges from their right. In Texas on May 28, moderate Rep. Tony Gonzales faces a runoff against YouTuber Brandon Herrera that has attracted millions of dollars in advertising and has gotten very personal in recent weeks. In West Virginia, Rep. Carol Miller has begun airing negative ads against her opponent, former state Rep. Derrick Evans, ahead of her May 14 primary. And two South Carolina Republicans are facing competitive primaries on June 11. In the 1st District, Rep. Nancy Mace faces former state health department director Catherine Templeton in a primary that has seen the anti-tax Club for Growth and other super PACs invest millions; in the 4th District, Rep. Will Timmons and his allies are taking seriously a challenge from state Rep. Adam Morgan.

But wait, there's more: Florida Rep. Daniel Webster nearly lost his primary last cycle after being caught flat-footed and will have to get past former state Rep. Anthony Sabatini for his 11th District seat on Aug. 20. And Washington's 4th District Rep. Dan Newhouse might have a serious fight on his hands in his Aug. 6 primary, which also includes Trump-backed former NASCAR driver Jerrod Sessler and 2022 Senate nominee Tiffany Smiley. Newhouse only won 25 percent of the vote in the 2022 all-party primary for this seat, so he's clearly vulnerable. But no Democrats have filed to run yet, and Newhouse — who voted to impeach Trump in 2021 — stands a better shot of winning the bulk of those Democratic votes than Sessler or Smiley.

On the Democratic side, the two members most likely to encounter serious primary trouble are both members of the progressive "Squad." In New York's 16th District, Rep. Jamaal Bowman is fending off a well-funded challenge from Westchester County Executive George Latimer; the June 25 primary will be among the most expensive this election cycle if the AIPAC-affiliated United Democracy Project gets involved. And Missouri's 1st District Rep. Cori Bush was trailing by double digits against St. Louis County prosecutor Wesley Bell in the only public survey of her Aug. 6 primary.

—Jacob Rubashkin, Inside Elections

As Meredith alluded to, the GOP primary in the 5th District is competitive today after Spartz decided to seek reelection, but only after a Hamlet rendition of "to run or not to run."

In February 2023, Spartz surprised the political world by announcing that not only would she not run for Indiana's open Senate seat, she also wouldn't seek reelection. She then repeatedly flip-flopped on whether she might reconsider her decision before announcing in February that she would indeed seek reelection, just days before the filing deadline. Spartz's decision upset the plans of the many GOP contenders who'd entered the race in the meantime — 11 candidates (including Spartz) are on the primary ballot.

However, state Rep. Chuck Goodrich looks like a real threat to Spartz. The CEO of an electrical contracting company, Goodrich has self-funded heavily — $4.6 million of the $5.5 million he'd raised as of April 17 — to give himself a significant financial advantage over Spartz, who had only raised $581,000 after barely fundraising throughout 2023. Even with the money she already had in the bank, Spartz has been outspent $4.1 million to $2 million by Goodrich.

Goodrich has emphasized his America First views and attacked Spartz, most notably by casting her as overly supportive of Ukraine in its war against Russia. Spartz is Ukrainian American, and Goodrich has claimed she's been "putting Ukraine first" while using an image of Spartz with Biden after the passage of Ukraine military aid in 2022. However, Spartz's record is more nuanced: She has been critical of Ukrainian President Volodymyr Zelenskyy and opposed the most recent round of Ukraine aid that Congress passed in April.

Yet Goodrich's attacks may be working: A late March poll for his campaign by pollster Mark It Red found him almost running even with her, trailing just 33 percent to 30 percent — a change from earlier polls that gave the incumbent a larger lead.

—Geoffrey Skelley, 538

There are two women among the six Republicans vying to be Indiana's next governor: Crouch and Jamie Reitenour. Reitenour, a political newcomer, is unlikely to garner much support, but theoretically, Crouch should have a pretty good shot — she is the current lieutenant governor of the state and has been endorsed by dozens and dozens of local officials. Unfortunately for her, though, polls show her running well behind Braun, who has been endorsed by Trump and the Club for Growth. The current Republican governor, Holcomb, has also declined to endorse his second in command: "I don't want anyone thinking that just because she and I work so closely together that she's a clone of me."

Notably, Indiana is one of 18 states that has never had a female governor. So Crouch would make history if she wins the primary. But Crouch's underdog status is emblematic of an overall chilly environment for female candidates in Indiana. Just 27 percent of the state's legislature is women, which is below the national average (33 percent), and according to our analysis of data from 1983 to 2019, the state was usually below the national average. Both senators currently representing the state are men. (In fact, Indiana has never elected a woman to the Senate, and of Indiana's nine House members, just two are women.)

Today, Indiana has the chance to either increase or decrease that number. Rep. Erin Houchin in the 9th District, who will face one challenger, will have no problem winning reelection. In addition to having Trump's endorsement, she's supported by VIEW PAC and Maggie's List, groups that are working to elect more GOP women to Congress. However, in the 5th District, Spartz faces a crowded and competitive primary after rescinding her retirement announcement (as Geoffrey will explain in more detail in a few minutes). Trump has stayed out of that race, but VIEW PAC is backing Spartz.

However, as Nathaniel wrote earlier, Republicans could nominate a woman, Davis, in the open 3rd District. Two of the women's groups we are watching — VIEW PAC and Winning for Women — have endorsed her in that race.

—Meredith Conroy, 538 contributor

Indiana's primary for governor is the most interesting statewide contest on tap today. And the action is all on the GOP side of the aisle because the solidly red state will likely elect another Republican to succeed term-limited GOP Gov. Eric Holcomb. The leading candidate looks to be Braun, who won a Senate seat in 2018 but decided to run for governor instead of reelection this cycle. Yet Braun has three notable challengers for the Republican nomination: former state Commerce Secretary Brad Chambers, current Lt. Gov. Suzanne Crouch and businessman Eric Doden. A fourth, former state Attorney General Curtis Hill, has notoriety but for all the wrong reasons: He lost renomination for his old office in 2020 after allegations came out that he had groped a group of women at a party.

For Braun, the good news is that none of his opponents have broken out from the rest of the pack. In early April, a SurveyUSA/Howey Politics/Indiana State Affairs poll found Braun at 44 percent among likely primary voters, with Crouch, Chambers and Doden all at around 10 percent, similar to the findings in older polls of the race. However, Braun's opponents have certainly put together the resources to push for a breakthrough. Overall, Braun had raised $10.2 million as of March 31, but Chambers had raised more ($12.8 million) and Doden about the same ($10 million) — thanks partly to millions from Chambers's own pocket and Doden's family.

Crouch hasn't raised as much (around $7 million post-2020), but she did enter the last weeks of the campaign with $3.1 million in the bank, more than Braun, Chambers or Doden. The field has spent their resources mainly to bring Braun down a peg and promote their candidacies, in particular seizing upon comments Braun made in 2020 following the police murder of George Floyd in which the senator appeared supportive of Black Lives Matter, a conservative apostasy.

—Geoffrey Skelley, 538

ABC News reports that state Sen. Mark Messmer is projected to win the crowded GOP primary in Indiana's 8th District, which is currently held by Rep. Larry Buschon. Messmer defeated former Rep. John Hostettler and several other candidates in a race that attracted significant outside spending.

—Jacob Rubashkin, Inside Elections