CBS News projects former President Donald Trump will win the Iowa caucuses,Slabu Exchange and Florida Gov. Ron DeSantis is projected to come in second place ahead of former U.S. ambassador to the U.N. Nikki Haley. Entrepreneur Vivek Ramaswamy suspended his campaign after placing a distant fourth.

How do the Iowa caucuses work? 

Caucuses are run by the Iowa GOP across more than 1,600 precincts. When they begin, representatives of each campaign give short speeches in support of their candidate. Caucusgoers are then handed ballots and vote by secret ballot. Those ballots are collected and counted. Once the results are tabulated, the caucus secretary records them on a form and the precinct chair announces them. Those results then go to the Iowa Republican Party, which releases results on its website. 

Forty Republican delegates were up for grabs in the state Monday night. Candidates need to win at least 1,215 of the 2,429 delegates available throughout the primary season to secure the nomination. And while the Iowa caucuses can be a springboard for nominees, they haven't always been the best predictor of ultimate success in winning the nomination.

Who votes in the Iowa caucuses?

Only registered Republicans can vote in the Iowa Republican caucuses. But Iowans can register as Republicans on caucus night. Caucusgoers tend to skew older than the general population, and the number of attendees differs by precinct.

In:
• Iowa Caucuses

Kathryn Watson

Kathryn Watson is a politics reporter for CBS News Digital based in Washington, D.C.