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

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.

According to the polls, Trump is on his way to a huge win in Iowa, while Haley and DeSantis are in a close race for second place. As of 9 a.m. Eastern this morning, when we ran our Iowa polling average for the last time, Trump was polling at 53 percent on average, Haley was at 19 percent, DeSantis was at 16 percent, Ramaswamy was at 6 percent and Hutchinson was at 1 percent.

Believe it or not, though, Trump's lead is even bigger nationwide. According to our national polling average as of 2 p.m. Eastern, Trump was at 63 percent, Haley and DeSantis were at 12 percent each, Ramaswamy was at 4 percent and Hutchinson was at 1 percent.

In other words, Trump is sitting pretty.