Romney and all of the Republican candidates are pursuing party delegate votes, something President Obama doesn't have to do.
Exactly. And four years ago, when the shoe was on the other foot, Obama and Hillary nearly tore the party apart. Cooler heads finally prevailed, and now they work together (although I suspect it's an uneasy truce).
I'm not sure if that will be the case with the Republicans this year. I don't think Gingrich would mind splitting the party by going out in a blaze of glory.