It's just worth remembering that the real GOP field this time was at least Romney, Pawlenty, Perry, and Barbour, and perhaps also several others, including Palin, Thune, Christie, and Daniels. That's the real field that we should consider when assessing what Romney beat. Most of the others who showed up for debates and even took votes in some primaries, such as Herman Cain and Newt Gingrich and Michele Bachmann, were just sideshows.It gets a bit fuzzy when we try to determine exactly who the field of candidates is in a given year, since many of them are selected out during the invisible primary stage, long before anyone begins voting or conducting debates. Kerry wanted to run in 2008. Gore wanted to run in 2004. So did Daschle. But after enough discussions with potential donors, activists, and endorsers, they became convinced it wouldn't happen, so they decided not to run.
What's more, it's often the highest quality candidates -- the ones who understand the difference between a winnable and an unwinnable campaign -- who select out of the pool the quickest. The Pawlentys and Christies of the world likely looked at the way the field was shaping up (specifically, how much inside support Romney had) and figured they just couldn't make it happen this year. The people who are left in by the time the voting starts either don't realize they can't win (Bachmann, Santorum), are just trying to raise some issues of importance (Paul), or have nowhere else to go (Gingrich).