I'm an Idahoan, so this take might be wildly insular, but I think that Republicans in western states (like Colorado and Utah) are still able to put forward candidates that are conservative enough to ward off Trumpian (typically newcomer) candidates with anti-democratic tendencies, armed with conservative bona fides that still serve what Trumpian conservatism feeds, like anti-establishment, anti-authority authenticity. But it is of a frontier flavor that I think Trump and many Trumpy candidates don't have.

—Meredith Conroy, 538 contributor

It's not exactly breaking news that Trump has a strong hold over the GOP. But if you look at the three cases where his endorsees lost tonight, each pick had potential challenges, either because of their own weaknesses as candidates or strong candidates running against them. In South Carolina's 3rd District, Mark Burns had a controversial past that invited outside spending to help his opponent, and Burns also barely raised any money from donors, mostly self-funding his bid with loans. In Colorado's 5th District, Dave Williams had rubbed a lot of people the wrong way as state party chair, to the extent that outside groups spent more than $2.6 million against him or on behalf of his main primary opponent. And Trump doesn't have as firm a hold over GOP politics in Utah, indicative of how his endorsee, Trent Staggs, couldn't beat out the establishment choice in Rep. John Curtis, who had a stronger track record as an incumbent congressman and received a ton of outside support.

—Geoffrey Skelley, 538

Trump made some ill-advised endorsements in today's races, and it feels to me like they were based more on his own personal taste rather than any kind of strategy. Williams in Colorado’s 5th District has been very outspoken, he’s an election denier, he’s made controversial, identity politics stands as the state GOP chair, and it could just be that Trump liked his MAGAness or the fact that he seized control of the state party in the way he did. I doubt his team would have chosen Williams as the endorsee, I suspect this was all Trump, and a similar scenario may have happened with Staggs and Burns.

—Kaleigh Rogers, 538

Going into tonight, Trump had only endorsed one candidate for Senate, House or governor who lost. Tonight alone, he endorsed three. Why do you guys think Trump failed so badly tonight? Was it just bad luck, or something real?

—Nathaniel Rakich, 538

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