With his second victory in a row, Mr. McCain is now clearly the favorite for the nomination that eluded him in 2000 and that again seemed out of reach only three months ago. He turned back Mr. Romney thanks to the votes of seniors, veterans and self-described moderates and independents. He also did well in the Miami-Dade and Tampa strongholds of the state's popular Republicans who endorsed him, Senator Mel Martinez and Governor Charlie Crist. In Florida, the Republican establishment coalesced around the Senator like it never has before. Mr. Romney nonetheless won narrowly among Republicans, and more broadly among...