Following a visit to his Michigan campaign headquarters on Feb. 28, Mitt Romney told reporters that Republican voters should choose the party's nominee. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Mitt Romney greets patrons at a restaurant called The Mitt in Mount Clemens, Mich., on Friday. The candidate hasn't done as much handshaking lately, given the size of the recent primary states. Gerald Herbert/AP hide caption

itoggle caption Gerald Herbert/AP