Even if the controversy over Arizona’s immigration law simmers down over the next two years, there’s an obvious political problem in approving Phoenix this summer. And as long as Mitt Romney remains the man to beat in 2012, the prospect of a convention in the home of the Mormon church is, rightly or wrongly, worrying to many Republicans. So look hard at Tampa, envision a keynote address by a Senator Marco Rubio or a Congressman Allen West, and it’s easy to figure out why Republicans might like this this option.