Do Republicans believe Marco Rubio? While much of the political world had been obsessing over decisions by Chris Christie and Sarah Palin not to run for president, the freshman senator from Florida has been making a series of increasingly Shermanesque vows to turn down any offer to join a Republican ticket as a vice presidential candidate.

If Rubio sticks to his guns, it would be a crushing disappointment for many Republicans. At a recent GOP straw poll in Michigan, conducted just after the Republican debate in Orlando, Rubio was the solid winner in the vice presidential category, beating current presidential candidates (and eventual VP possibilities) Herman Cain, Newt Gingrich and Michele Bachmann.