I think Jamelle has all the essential points down in advance of the Florida results being announced. I think most people are going to accept what should have been obvious as soon as Rick Perry (the one candidate who could have been a conservative alternative to Romney with enough establishment support to compete) imploded: Romney is the Republican nominee. I doubt Gingrich would have had any chance even if he was running a serious campaign from the beginning, and he wasn’t. At any rate, after tonight nobody is going to think Newt can win, so anybody wanting to avoid acknowledging Romney’s inevitability is going to have to contrive some kind of white knight scenario. But that’s obviously not to happen — it will be literally impossible for a new candidate to win, and while it’s theoretically possible for a new entrant to force a brokered convention Jamelle is right that nobody has the “considerable fundraising and organizational ability, a national constituency, and a message that can appeal to a broad swath of the Republican Party,” that would be necessary. (And, in addition, there’s the fact that Bill Kristol’s fantasy candidates just don’t want to run. It’s not as if Romney’s vulnerabilities weren’t obvious last year; if Daniels or Ryan or whoever wanted in they would have done it when they could win. And after tonight, Romney will be a lot less vulnerable.)
Romney will be the candidate, and Republican voters will reconcile themselves with him very quickly. I very much doubt that Newt or Santorum are in this for the long haul, but I also don’t think it matters.