Another interesting question a possible Rubio candidacy raises is whether there is enough room in the primaries for both him and Jeb Bush. The answer, given their overlapping bases of support and positions, is probably no. My guess is that Rubio is the more likely to run, but Bush — given his built-in advantages in the race to become the establishment candidate — might be the more formidable contender.
Scott Walker, the governor of Wisconsin, is being mentioned as a dark horse so frequently that he is rapidly ceasing to be one. The case for Walker bears some resemblance to the case for Tim Pawlenty, then the governor of Minnesota, four years ago. Like Pawlenty, Walker is a northern evangelical and a successful governor of a blue state in a region of the country Republicans lust after. He has a great advantage over Pawlenty, though, in that the political battles in his state attracted national attention.