Republican presidential candidate, former Massachusetts Gov. Mitt Romney, followed by, from second from left, Florida Senate candidate, Rep. Connie Mack, R-Fla., Sen. Marco Rubio, R-Fla., and former Florida Gov. Jeb Bush arrive in Miami for a Romney campaign event, Wednesday, Oct. 31, 2012. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

Republican presidential candidate, former Massachusetts Gov. Mitt Romney, followed by, from second from left, Florida Senate candidate, Rep. Connie Mack, R-Fla., Sen. Marco Rubio, R-Fla., and former Florida Gov. Jeb Bush arrive in Miami for a Romney campaign event, Wednesday, Oct. 31, 2012. (AP Photo/Charles Dharapak)