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

Amid the many primaries taking place tonight, voters in Colorado's 4th District are also choosing their next member of Congress. Buck, frustrated with his own party, resigned from the House early, triggering a special election to fill out the remainder of his term.

Though Boebert is running for a full term in this district, she isn't running in the special. Instead, Republicans nominated Greg Lopez, the former mayor of Parker, Colorado, and a 2022 candidate for governor. Lopez faces Democrat Trisha Calvarese, a speechwriter, in what should be an uncompetitive special election tonight.

But there's at least an outside possibility the race could surprise us. Democrats recently overperformed in another House special election, in Ohio's 6th District, that was thought to be a walkover for the GOP. That seat, vacated by Republican Bill Johnson, had voted for Trump by 29 percentage points in 2020, but the GOP nominee won by 9 points, an overperformance of 20 percent. Colorado's 4th District voted for Trump by 19 points in 2020, so a similar overperformance would result in a very tight race.

However, there are plenty of reasons why that may not be the case. Unlike in Ohio, where the special election was the only race happening in the state and turnout was in the basement, the Colorado special election is concurrent with a statewide primary race that will boost turnout. And in the 4th District specifically, a contentious primary featuring Boebert and a bunch of other candidates will probably boost Republican turnout specifically.

But it wouldn't take a Calvarese win to be good news for Democrats. Historically, special election results have some predictive power, and Democrats have been putting together a healthy record so far ahead of the 2024 elections. Since the beginning of 2023, Democrats have overperformed partisanship in House special elections by 7 points, according to a 538 analysis, and in special elections overall by a similar margin.

At a moment when national polling looks middling at best for Democrats, a stronger-than-expected showing tonight could provide some much-needed comfort.

—Jacob Rubashkin, Inside Elections