particularly given the circumstances surrounding the weather, the fact that it's expected to be the coldest iowa caucus that has ever been recorded in history with temperatures hitting potentially below 10 or below 15 degrees. these candidates, nikki haley telling her supporters that they're going to have to bundle wear layers, but imploring them to get out and making their final pitches in the hours before they actually go and vote. victor, amara? >> all right. thank you. the polls show that donald trump could score this historic win i that are up for grabs after former new jersey governor chris christie dropped out of that race. >> which candidate will benefit most from his exit? cnn's omar jimenez has more. >> reporter: chris christie hasn't endorsed anyone yet, but there's one candidate most likely to benefit from his exit. a cnn poll from new hampshire showed 65% of christie voters