Iowa caucus 2024: Full results

Donald Trump scored a decisive win, while Ron DeSantis edged Nikki Haley for second place.

Former President Donald Trump won the Iowa caucuses in his bid to reclaim the Republican nomination this year.

The Associated Press quickly called the race Monday night as early results showed Trump with a decisive lead over GOP rivals Florida Gov. Ron DeSantis, former U.S. ambassador to the U.N. Nikki Haley and entrepreneur Vivek Ramaswamy. DeSantis finished second, Haley in third and Ramaswamy a distant fourth — leading him to suspend his campaign and endorse Trump.

The New Hampshire primary takes place next, on Tuesday, Jan. 23.

How the caucuses work

Iowa has long been influential in deciding which candidates gain early momentum in the presidential race. And that is a lot of power for a state that doesn't rank in the top 30 in total population. These voters will play a significant role in deciding who millions of Americans choose from in the general election this fall.

Iowa is one of the few states that conducts a vote by caucus rather than simple ballot. A caucus involves listening to speeches by representatives of each candidate’s campaign, and then casting a ballot after that. Iowans can’t just go to the polls anytime they want on Election Day.

The first Iowa caucuses took place in 1972, for Democrats only. Republicans followed in 1976. Parties picked their nominees at their conventions prior to that.

For more on the caucuses and results, check out Yahoo News' live blog.

(Thumbnail photo: Andrew Harnik/AP)