Iowa caucuses 2024: Trump projected to win, DeSantis 2nd

Hello! I’m Meredith Conroy, a politics contributor at 538. I’m a political scientist at California State University, San Bernardino, who studies the role of gender and media in American politics. Tonight, I’ll bring a political science perspective to the conversation (probably in the form of links to academic articles that are too long). I’ll also be watching closely to see where (and among whom) Haley is performing well. She’s got most of her eggs in the New Hampshire basket, but could claim a moral victory in Iowa if she can stay competitive with DeSantis.

In Iowa tonight, our delegate benchmarks suggest Trump needs to win just 12 of 40 delegates to be on track to win the overall majority by July. To do so he will need 30 percent of the vote (our average of polls has him getting 53 percent). Meanwhile, DeSantis and Haley need to win 22 and 26 delegates, respectively, in order to be on track to win the nomination. Either would have to beat their polls dramatically to win such tallies.

The difference in these projections boils down to where the candidates draw their strength from. Our model looks at polling, demographics and political data in every state to project how many delegates we can expect each candidate to win from every contest. We then adjust candidate support in each state until those projections add up to a majority of delegates — the threshold needed to win the nomination. DeSantis and Haley are more popular with moderate, college-educated and anti-Trump voters, who are overrepresented in early states. That means they need lots of delegates from those states to win. In contrast, thanks to strength among non-white and evangelical Republicans, Trump is projected to do better in states that vote later in the primary calendar. That means he can stay on track to win even with a poor performance, compared to his polls.

Of course, the outcome of tonight’s caucuses will also alter the shape of the race. For example, a bad showing for Trump could catapult his rivals to success in later states. Our benchmarks are not forecasts for those contests. Once we have results from each contest, or the polls change significantly, we will update our benchmarks for future states.

According to a January Selzer & Co./Des Moines Register/NBC News/Mediacom survey, 34 percent of likely Republican caucusgoers say they will be voting in the Iowa caucuses for the first time, while 66 percent say they have attended at least one caucus in the past (Republican, Democratic, or both). Throughout the campaign, Selzer polls have shown steady growth in the number of likely voters that say they are first-time caucusgoers, increasing 15 percentage points from the first time the question was asked in August 2023.

We expect Iowa Republicans to have a very white, fairly religious and relatively conservative electorate. To start with, the state is very white. Among the 50 states, Iowa has the sixth-largest non-Hispanic white population share (84 percent). White voters make up a large part of the Republican base nationally, and as Iowa is whiter than most places, the GOP ends up having an almost entirely white electorate there: In 2016, for instance, the National Election Pool entrance poll found that 97 percent of Republican caucusgoers identified that way.

White evangelical Christians will also play a big part in the caucuses. After all, at least 56 percent of the electorate identified as such in the 2008, 2012 and 2016 GOP caucuses, per the entrance polls. Iowa's population as a whole is 19 percent white evangelical Protestant, according to the Public Religion Research Institute, which places it a bit above the national share of 14 percent. But white evangelical Christians are among the Americans most likely to identify as Republican, so we'd naturally expect them to be a more significant force in a GOP nomination contest. (We do have to be wary about the term "evangelical," which has become more inextricably linked to politics at the expense of its religious meaning.)

Lastly, there's good reason to expect a fairly conservative electorate. In 2016, the entrance poll found slightly more participants identified as "somewhat conservative" than "very conservative" — 45 percent to 40 percent — but more voters said they were very conservative in 2008 and 2012. In all three years, no more than 15 percent identified as "moderate." And generally, low-turnout caucuses tend to have more ideologically extreme participants than primaries.

This is in no small part due to higher barriers to participation. Only voters registered as Republicans can participate in party caucuses, which are a time-consuming, one-time event — unlike primaries where voters have all day to cast a ballot (and usually some option to vote by mail). In 2016, a combined 16 percent of Iowa's voting-eligible population took part in the Democratic and Republican caucuses, according to the U.S. Elections Project. This marked the highest turnout for any state using caucuses, but that figure was lower than the turnout in any state that held both a Democratic and Republican primary. Ultimately, the caucus system results in a low-turnout nominating event that magnifies the involvement of the party's most committed members.