conditions, iowans will gather at locations across the state from church basements to school cafeterias to discuss the republican candidates and vote. and the results could dramatically reshape or solidify the landscape of the presidential race. in the final hours, three big questions for the three leading candidates -- >> we're going to take our country back. >> first, donald trump. >> look, we got to get out and vote. >> the record margin in a contested gop caucus is 12 points, but with a lead of more than 30 points in the latest iowa polls, how big does trump's win have to be? >> we're delivering on the promise to do all 99. >> then there's ron desantis. >> we're in it for the long haul with this. >> he's put all his chips on iowa. barnstorming the state with more than 100 events across all 99 counties. but if he doesn't win or come close, will he drop out? >> if you will caucus for me, i will forever be grateful. >> then there is nikki haley --