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

All eyes are on the horse race tonight to see who will emerge victorious from the first-in-the-nation contest for the Republican presidential nomination. Polls have long told us that Trump is a clear favorite — but what issues are motivating Republican caucusgoers in Iowa, and are they in line with their party nationally?

On immigration, Republican caucusgoers in Iowa are far to the right, and seem to agree with some of Trump's stated plans. In an October Selzer & Co./Des Moines Register/NBC News/Mediacom poll, 80 percent of likely caucusgoers said immigration and border security were extremely important to them. A survey from the same pollsters in December found that, when asked about Trump's statement that immigrants who enter the U.S. illegally are "poisoning the blood of America," a plurality of 42 percent of likely caucusgoers said the statement made them more likely to support him. A slim majority, 50 percent, also said they were more likely to vote for Trump when he promised "sweeping raids, giant camps and mass deportations" as an immigration policy. Trump's rivals seem to have taken cues too, as they've embraced more extreme policy rhetoric on immigration and invested in ads focused on the issue.

And on abortion, Republican caucusgoers seem to lie a bit further right than other Republicans. 75 percent want abortion in Iowa to be illegal in all or most cases, per a YouGov/CBS News poll conducted in December>, and half said they wanted the Republican nominee for 2024 to be someone who would support a national abortion ban. These are higher numbers than we've seen in similar national polls of Republican primary voters, and could put some voters off both Trump and Haley, who have been dinged for moderating on the issue during the campaign.

Continued use of ethanol as a gasoline additive is another, more Iowa-specific, issue in the state; as much as half the state's corn crop is used in ethanol production. Per a November ARC Insights/Fields of Freedom survey, overwhelming majorities of Iowa caucusgoers think ethanol is important to both energy independence and the national economy, and want their candidate to include its use in a national energy policy. That means they're likely not fans of the Biden administration's push to expand production and use of electric vehicles — a talking point that most Republican candidates have taken up.

Iowa — along with early-state buddy New Hampshire — has helped shape the results of presidential contests since the dawn of the modern nomination system in the 1970s. The caucuses have provided a pivotal opportunity for candidates to exceed expectations from the start and grab what George H.W. Bush called the "Big Mo" — momentum — after his 1980 Iowa win made him one of the leading Republican candidates that cycle.

The threshold for what could be considered a good or bad performance for each candidate is a moving target influenced by poll numbers, political media and a candidate's own expectations-setting. Beating those marks can raise a candidate's viability in the eyes of the press, donors and voters, precipitating increased and more positive media coverage, stronger fundraising and greater support in later electoral contests. This year, with Trump holding such a large lead, a bigger question than whether he will win is what his percentage looks like and how the rest of the field does in comparison.

Each Republican contender tonight has different goals to meet. For Trump, it's mainly about meeting the expectation of a sizable win — a win with less than an outright majority might look weak for a candidate who is polling north of 50 percent in Iowa. For DeSantis, success appears to be a matter of finishing in front of Haley for second place; otherwise, his campaign may be kaput. Haley, meanwhile, could bring about DeSantis's demise with a solid second-place performance, and set herself up to keep the momentum going into New Hampshire, where she's polling far better. And for Ramaswamy, it's about staying relevant and getting into the double digits.

As you await tonight's caucuses, allow me to make a humble suggestion: Get up to speed on everything you need to know to interpret the results by listening to the latest 538 Politics podcast. After the final pre-Iowa debate — the cycle's first head-to-head faceoff between Haley and DeSantis — my colleagues Nathaniel Rakich, Leah Askarinam and Elliott Morris sat down with me to talk about what we'd watched and what to expect coming into tonight. We had some fun too!

Generally speaking, a caucus is an event where party members gather to conduct party business. In a presidential year, that can include electing delegates to the next step of the multilevel national delegate election process — that is, the selection of the actual people who will go to the county convention, which then picks delegates for the state convention, where the national delegates are then chosen. How a caucus functions depends on the state and the party's rules. In some states, like Iowa, a caucus includes a presidential vote by participants that allocates national delegate slots to candidates that are then filled by the selection process. In others, the state party may use a caucus-convention system to select the individuals who'll serve as delegates, but actually allocate national delegate slots using the state's presidential primary.

Today in Iowa, Republicans are holding precinct caucuses to begin their national delegate selection process (Iowa Democrats will also hold them, but no longer use them to allocate national delegates). Run by the party, the GOP meetings take place in the evening at government centers, schools, churches, businesses and even homes. Prior to the preference vote, the caucus chair at each caucus will invite one attendee each to speak on behalf of each of the candidates. Then, each attendee casts a presidential preference vote, which gets reported to the wider world. The results of these votes statewide will determine how the state's 40 national delegates are allocated. (Before 2016, this much-watched vote was actually non-binding and played no direct role in the Republican allocation process.) Following the preference vote, attendees can stay to participate in party business, including electing precinct committee members and selecting county convention delegates.

While most states hold primaries, Iowa Republicans are not alone in using a caucus vote to allocate delegates: Seven states lack a presidential primary law, and most territories use a caucus-convention or other party-run event, too. Even in primary states, a party can forgo an available primary option to allocate delegates with a party-organized event, such as a caucus or party-run primary. Nevada is a prominent example this cycle: There, the state GOP opted to use caucuses on Feb. 8 to allocate delegates instead of the state's primary on Feb. 6, although a Republican primary will still occur.