New Jersey Gov. Chris Christie waves as he stands with his wife Mary Pat Christie during a gathering for his swearing in for his second term Tuesday in Trenton, N.J. Mired in a scandal, Christie sought to turn back the clock Tuesday and focus on the mandate he said he got in November to "stay the course" and put aside differences, even as Democrats ramped up an investigation into whether his administration abused its power. (AP Photo/Mel Evans)

Question: Who will Republicans turn to for a presidential nominee, if they can't pick Christie?