That’s true, Monica, Haley supporters are particularly unenthusiastic about a potential Trump nomination. In the latest Selzer & Co./Des Moines Register/NBC News/Mediacom Iowa poll, 54 percent of likely caucusgoers who said they would caucus for Haley also said it would be nearly impossible for Trump to win against Biden given his legal challenges, compared to only 23 percent of caucusgoers overall.

But strikingly, most of Haley’s supporters said they wouldn’t support Trump in the general anyway. While 71 percent of likely GOP caucusgoers overall said they’ll vote for Trump in November if the race is between Trump, Biden and Kennedy, just 23 percent of Haley supporters would vote for the former president. Forty-three percent said they would choose Biden, while the rest said they would choose Kennedy or another third-party candidate, would not vote or were not sure.

So if she does well tonight, I wonder if we’ll see her less reluctant to criticize Trump in the future, since it may not be that detrimental to her base of support.

As Galen posted earlier, the weather in Iowa tonight is downright nasty — below zero even without the wind. There’s been a lot of speculation about how that could affect the results tonight, so I wanted to get everyone’s two cents! Do you think any candidate in particular would benefit from a low-turnout scenario?

Personally, I think Trump might be the beneficiary. According to the final Selzer poll of the race, 49 percent of Trump supporters said they were extremely enthusiastic about their candidate. But only 23 percent of DeSantis supporters said the same, and 9 percent of Haley supporters did.

Sarah McCammon of NPR was with Haley as she addressed supporters in Adel, Iowa, tonight, and said Haley supporters are still hoping there's an opening for someone who isn't Trump to win the Republican nomination. It got me thinking about how strongly Trump defines this race, whether caucusgoers want to vote for or against him. That's what I'll be thinking about as we watch this first contest of 2024 play out. We're in an unusual situation: Many Republicans view Trump almost as an incumbent. If he wins the nominating contest he'll probably face another incumbent in Biden, who likewise seems to have his party's nomination locked in. Because of Trump's continued popularity, opponents like Haley and DeSantis have been reluctant to criticize Trump too much, which leaves them a bit at a loss when they're trying to convince supporters to choose them over the frontrunner. McCammon said Haley called Trump the right candidate in 2016 but said he's sewn "chaos" since then. Chaos might be a nice word for everything that happened after Trump lost to Biden in 2020 and the criminal charges the former president still faces. As we head into what increasingly looks like a potential rematch, it's hard not to wonder if more chaos will ensue.

There's been a lot of talk about whether any candidates will have an unexpectedly strong showing tonight and make the race more competitive. But these early contests usually play a different role: winnowing. Candidates who make it this far tend to hold out for a few more bites at the apple, with Super Tuesday marking a big winnowing moment. But there are always candidates who are depending on a strong showing in Iowa to save their candidacies, sometimes for geographic or ideological reasons. And these candidates sometimes treat Iowa as their cue to exit.

In 2016, Martin O'Malley left the Democratic race after results in Iowa confirmed that he wasn't much of a contender next to Hillary Clinton and Bernie Sanders. Republican Mike Huckabee also dropped out in 2016 after a disappointing performance, especially compared to his 2008 strength in the evangelical stronghold. In 2012, Minnesota Republican Michele Bachmann ended her campaign after coming in sixth — damaged not only by Iowa's critical role for lesser-known candidates, but also by the presumption that, because of the similarities with her neighboring home state, Iowa should have been friendly territory. In 2008, the Iowa caucuses seemed like they should have been a strong area for Democrat John Edwards, who campaigned extensively there with an economic populist message. But he came in second to Barack Obama, whose campaign presented the victory as a major statement about his broader electoral appeal, and stayed in the race for just a few more weeks. And then there was the famous "Dean scream" the night of the 2004 Democratic caucuses, after Howard Dean's Iowa support failed to live up to the excitement around his candidacy. This might not have doomed his presidential bid right away — he left the race after finishing third in Wisconsin — but it probably didn't help.