Donald Trump and Fox News are at odds again, after the Republican presidential candidate criticized host Megyn Kelly. "Donald Trump rarely apologizes, although in this case, he should," Fox chief Roger Ailes said. Mark Wallheiser/Getty Images hide caption

toggle caption Mark Wallheiser/Getty Images

Republican presidential nominee Mitt Romney speaks at a campaign fundraising event in Salt Lake City on Tuesday. Charles Dharapak/AP hide caption

toggle caption Charles Dharapak/AP

Republican presidential candidate former Massachusetts Gov. Mitt Romney, right, makes a point as Texas Gov. Rick Perry listens, during a debate in Orlando, Fla. Phelan M. Ebenhack/AP hide caption

toggle caption Phelan M. Ebenhack/AP