Trump has endorsed 18 candidates in Republican primaries tonight, though 12 are incumbents. Trump's track record of picking winners has been very strong this primary season — so far, only one candidate he endorsed for Congress or governor races has lost her primary: Mendham Mayor Christine Serrano Glassner in New Jersey's Senate race. But Trump often pads his numbers by endorsing candidates who are locks to win, and tonight he's made a few riskier calls that might lower his batting average.

Consider Colorado's 5th District, around Colorado Springs in the middle of the state. In the race to replace Lamborn, Trump has endorsed Williams over Crank. As I wrote earlier, Crank has the backing of traditional GOP groups that have spent millions opposing Williams, so Trump may have his money on the dark horse in this race.

A similar showdown is happening in Utah for Romney's seat. Trump is backing Staggs, but Curtis seems favored to win the GOP nomination.

I'll be tracking all of these races, and more, tonight to see where Trump's endorsement track record lands.

—Kaleigh Rogers, 538

Utah may be safely Republican, but the MAGA faction of the party is looking to pick up seats from the traditional Republican faction in Tuesday's primaries. And the biggest prize of all is the state's open U.S. Senate seat, currently held by anti-Trump Sen. Mitt Romney.

The front-runner to replace Romney is Rep. John Curtis, whose temperament — and attitude toward Trump — are closest to Romney's. Although he hasn't taken a high-profile stand against Trump like voting for impeachment, Curtis declined to endorse Trump during this year's presidential primaries and has avoided commenting on Trump's legal issues. Another tell: Though Romney hasn't made an endorsement, much of the incumbent's political operation is behind Curtis, who is known on Capitol Hill for being the rare Republican to talk about climate change and for owning 300 pairs of quirky dress socks.

Curtis faces three opponents who are, to varying degrees, more enthusiastic about Trump. Former state House Speaker Brad Wilson has raised the most money ($2.0 million from donors, $3.0 million from himself), but his efforts to strike a happy medium between moderate and MAGA (he introduced a resolution to pay tribute to Trump shortly after his second impeachment but also blocked an effort to censure Romney for voting to convict; he endorsed Trump for president, but only after Florida Gov. Ron DeSantis dropped out) may end up pleasing no one. Meanwhile, businessman Jason Walton has vocally defended Trump and is well funded thanks to a $2.5 million loan to his own campaign, but Trump himself opted to support underfunded Riverton Mayor Trent Staggs instead.

That surprising endorsement may have cost MAGA Republicans their best shot at defeating Curtis. Not only has Curtis raised $3.8 million on his own, but outside groups largely funded by moderate Republican donors have spent a whopping $9.6 million to help him or hurt Staggs. As a result, a [June 4-6 poll from HarrisX/the Deseret News/the University of Utah]) put Curtis at 47 percent support, with Wilson (24 percent), Staggs (21 percent) and Walton (8 percent) well behind.

—Nathaniel Rakich, 538

With 59 percent of the expected vote reporting in South Carolina's 3rd District GOP runoff, Biggs leads Burns about 53 percent to 47 percent, according to the AP. Looking at the returns and the county-level expected vote, Burns probably will gain some ground as we get more votes from Pickens and Greenville counties, which are counties he leads in and which have among the largest number of outstanding votes left to be tallied. However, with more than half the expected vote in, Biggs is probably at least a small favorite to win at this point.

—Geoffrey Skelley, 538

In the solidly red 24th District in Upstate New York, Republican Rep. Claudia Tenney faces a primary challenge from businessman Mario Fratto, who held Tenney to a 14-point win in her 2022 primary race. Having previously represented a seat located more in central New York, Tenney opted to run in the new 24th District in 2022 after redistricting even though she previously represented very little of it. Her weak performance partly reflected that unfamiliarity, but she's now a better-known quantity to voters in the region (and the 24th didn't change that much on a new map implemented earlier this year). Still, Fratto has tried to get to Tenney's right by claiming she's a "RINO" — Republican in name only — who has been insufficiently conservative in office. He's self-funded most of his challenge, raising $508,000 overall, but that's put him well behind Tenney's $2.0 million in receipts. Tenney has accused Fratto of being close to Nick Fuentes, a white supremacist and antisemitic leader — a claim Fratto denies. But she also felt threatened enough to run ads promoting her endorsement from Trump and attacking Fratto as "dangerously liberal."

—Geoffrey Skelley, 538