After GOP Rep. Jake LaTurner announced in April that he wouldn't seek reelection, five Republicans jumped into the primary race for his safe red seat in Kansas's 2nd District, which covers much of the eastern part of the state. Front-runner and former state Attorney General Derek Schmidt has high name recognition and a solid donor base in the state: He was his party's gubernatorial nominee in 2022, losing narrowly to Democratic Gov. Laura Kelly, and served as majority leader in the state Senate before his stint as AG. As of mid-July, Schmidt was leading the money race with over $497,000 raised as well as almost $287,000 in favorable outside spending.

His main opponents are former LaTurner staffer Jeff Kahrs, a veteran of both state and federal government who's self-funded more than two-thirds of the $433,000 he's raised, and rancher and feedlot owner Shawn Tiffany, a political newcomer who's raised almost $379,000. Schmidt notably tacked right during his gubernatorial run, and is likely trying to stay there, as both Kahrs and Tiffany are playing up their conservative bona fides. All three candidates have emphasized immigration and an "America first" conservative agenda, but Kahrs has branded himself as the "only conservative" in the race and prominently featured his role in the Trump administration (though Schmidt is the one with Trump's endorsement), while Tiffany has attacked Schmidt as a "career politician" and called him a "Republican in name only."

There's only been one poll in this race, and it was from ages ago (mid-May). While nearly half of respondents were still undecided at that point, Schmidt's name recognition clearly made him the candidate to beat: He had 44 percent support compared to Kahrs's 4 percent and Tiffany's 3 percent.

—Tia Yang, 538

Michigan is the only out-and-out battleground state voting on Tuesday, and its headline race is an open U.S. Senate seat that Democratic Sen. Debbie Stabenow's retirement has left up for grabs. On the Democratic side, Rep. Elissa Slotkin looks well-positioned to defeat actor Hill Harper: She's regularly polled above 50 percent in the primary contest while outraising Harper $24.1 million to $2.8 million.

Until a couple of weeks ago, the Republican primary contest looked at least somewhat more competitive. Former Rep. Mike Rogers, who retired from Congress in the 2014 cycle and had previously been critical of Trump, shifted his rhetoric and garnered the former president's endorsement in March, which along with his fundraising haul of $5.4 million has made him the favorite. Businessman Sandy Pensler, who'd self-funded almost all of his campaign's $5.0 million war chest, did seem to have the wherewithal to challenge Rogers. But on July 20, Pensler dropped out and endorsed Rogers, making the former congressman an even clearer favorite.

Now Rogers only has to contend with two other candidates, both of whom have criticized Rogers's conservative bona fides. The more notable name is former Rep. Justin Amash, who famously left the GOP to become an independent and voted to impeach Trump in 2019. In his campaign, Amash has run as a small-government critic of Rogers, whom Amash has accused of being an "establishment stooge" and part of the "deep state." Still, Amash has only raised $703,000, and while pro-Amash groups have forked out $1.7 million to boost him or attack Rogers, that's a far cry from the $5.0 million that outside groups have spent to help Rogers. Additionally, physician and pastor Sherry O'Donnell is running as an ardently pro-Trump candidate with endorsements from a number of far-right figures. But she's only brought in $434,000 and has received no outside assistance.

—Geoffrey Skelley, 538

The Republican primary in the dark-red 3rd District has gotten a fraction of the attention of Bush's contest in the 1st, but it has similarly high ideological stakes. Old-guard Republican Rep. Blaine Luetkemeyer is retiring, and it seems likely he will be replaced by a more hardline conservative, former state Sen. Bob Onder (whom Luetkemeyer also defeated in the 2008 primary en route to winning this seat in the first place). A bunch of GOP heavy hitters (Trump, the House Freedom Fund, the Club for Growth) have lined up behind Onder, who was known for his obstructionist ways in the state legislature.

Not everyone is thrilled about the prospect of Onder heading to Congress, however. Establishment-aligned super PACs have spent $4.9 million opposing Onder or supporting his main opponent, former state Sen. Kurt Schaefer, outdistancing the $3.0 million groups have spent to boost Onder or attack Schaefer. Luetkemeyer is supporting Schaefer as well, but it doesn't seem like he's catching on. Onder's campaign recently released a poll from Remington Research Group showing him leading Schaefer 34 percent to 14 percent, with five minor candidates combining for 16 percent, and 35 percent undecided. Even if we assume that poll is exaggerating Onder's support, it's unlikely that it's off by 20 whole percentage points.

—Nathaniel Rakich, 538

Perhaps no district in the country has seen more political activism in the past decade than Missouri's 1st District. In 2020, on her second try, now-Rep. Cori Bush — a progressive activist who first rose to prominence in the 2014 Ferguson protests in this district — defeated an entrenched incumbent representative in the Democratic primary in this safely blue seat, and she instantly made a name for herself as an activist legislator in Congress.

But her contrarianism — for example, she was one of just six Democrats to vote against President Joe Biden's infrastructure bill — has rubbed many the wrong way. It doesn't help, too, that the Department of Justice is investigating her for paying her husband for personal security services out of her campaign's bank account. As a result, Bush is now facing a serious primary challenge of her own from St. Louis County Prosecutor Wesley Bell.

Like Bush, Bell was first elected as a progressive in the wake of the Ferguson protests, but in this race he has inevitably become associated with the centrist and conservative donors and groups backing his campaign — most notably the American Israel Public Affairs Committee. AIPAC's super PAC has spent a whopping $8.4 million either supporting Bell or opposing Bush, who has been one of Israel's loudest critics in Congress over its conduct in the war against Hamas.

All told, pro-Bell groups have outspent pro-Bush groups $12.1 million to $2.9 million, according to OpenSecrets, and Bell's actual campaign has outraised Bush's $4.8 million to $2.9 million as well. But with all the advantages of incumbency as well as plenty of local endorsements, Bush will not be easy to defeat. A July 21-24 poll conducted by the Mellman Group/Democratic Majority for Israel gave Bell 48 percent support and Bush 42 percent, but since DMFI supports Bell and internal polls usually overestimate their preferred candidate's support, that implies the two candidates are neck-and-neck.

—Nathaniel Rakich, 538