Republican presidential candidates Florida Gov. Ron DeSantis and former U.N. Ambassador Nikki Haley participate in the CNN Republican Presidential Primary Debate in the Sheslow Auditorium at Drake University on Jan. 10, 2024, in Des Moines, Iowa.Chip Somodevilla/Getty Images

DeSantis and Haley barnstorm across frigid Iowa in the final days before the Republican caucuses

Trump is the heavy front-runner in Monday's caucuses.

14 Jan 2024, 02:04 by Adriana Gomez, Thomas Beaumont, Jill Colvin and Bill Barrow | The Associate Press, Adriana Gomez, Thomas Beaumont, Jill Colvin and Bill Barrow | The Associate Press · 5 NBCDFW