Romney’s support remains lukewarm. “People say, ‘I wrote him a check, but I’m not going to kill myself for him, like I did last time,’” a well-connected Republican said. “If you listen long enough, to enough people, you pick that up a lot.”

So insiders are closely watching a Pawlenty vs. Huntsman subrace, to see who else might show staying power.

There is one other scenario, and it terrifies Washington Republicans. That is the possibility that some very conservative, insurgent candidate will become the Romney alternative: former House Speaker Newt Gingrich, Minnesota Rep. Michele Bachmann, former Pennsylvania Sen. Rick Santorum or former Alaska Gov. Sarah Palin, if she defies conventional wisdom and winds up going for it.

“Republicans could have the situation that Democrats did in 1972, when the base of the party was so far outside the mainstream,” said one top Republican. Back then, George McGovern was the Democratic nominee and lost 49 states to President Richard Nixon.