In increasing order of likelihood, here are the five stop-Huckabee Republicans.
5) Rudy Giuliani
Rudy has fallen farther and faster than any mainstream media-anointed "front-runner" in memory. It's easy to see why.
First, Giuliani has an abrasive, schoolyard-bully character. It played well in New York; it doesn't play well in middle America. Richard Nixon had a similar persona, but:
A) It was a different time, when abrasive authority figures were the norm.
B) Giuliani is, believe it or not, usually more abrasive than Nixon.
C) Nixon's presidency ended disastrously.
Second, Republican primary voters have learned just how far left he leans on their hot-button social issues (abortion, gay rights, public prayer). He's not just farther left than the Republican field; he's farther left than Obama or Edwards, too.
Third, his inspired post-9/11 leadership is fading away. After all, voters have short memories, and 9/11 was nearly seven years ago. Also, he is more creature than creator of New York City's renaissance. Michael Bloomberg is a less flamboyant, but more effective, mayor than Giuliani ever was.
4) Ron Paul
Paul's support is coming from four extremely heterogenous groups:
1) The 2% of true-blue Libertarian Party members.
2) The 4% of conspiracy theorists. Some are attracted by Paul's old-fashioned isolationism. Others are drawn by his diatribes against paper money and his pledge to return the U.S. to the gold standard.
3) Under-30s (keep in mind that there are many more U30 Democrats than U30 Republicans).
4) A few (not all) fiscal conservatives who are tired of hearing candidates profess their belief in fiscal responsibility and then spend up a storm. Paul is the only one they trust to hold the line.
Given the odd lot under his banner and their small proportion in the electorate, Paul doesn't strike me as a serious contender.
3) Fred Thompson
Fred Thompson, like Ronald Reagan, is an affable actor who once played the President. Unlike Ronald Reagan, who wanted to be President very badly - to the point of nearly toppling a sitting Gerald Ford in the 1976 primaries - Thompson would like to be President, but doesn't want to fight hard for it. It's a shame, because he has some of the best people working for him and some of the best ideas of all the Republicans.
Thompson will hang around until he realizes that his competitors are hungrier than he is.
2) Mitt Romney
Romney has all the characteristics you want in a presidential candidate except sincerity.
Like John Edwards, he badly needed to win Iowa outright, but for different reasons: he needed to knock Huckabee and Paul out of the race. Iowa voters chose sincerity and (relative) poverty over Romney's flip-flopping, vast personal fortune, and Establishment backing. Now he is rapidly losing ground to McCain in New Hampshire. Like Hillary vis-a-vis Obama, if he stays close, he lives to battle on. If he loses big to McCain, he's fatally wounded.
1) John McCain
The Republican hierarchy has a simple, stark choice: swallow the poison pill, back McCain, and watch him - their only electable candidate versus Obama - prevail. In a delicious irony, it would mean backing him in South Carolina to beat Huckabee!
A bit of the old McCain from 2000 is creeping back: the grandfatherliness, the lack of patience with stupid questions, the unmatched devotion to a foreign policy worthy of America's values, the twinkle in his wizened eyes.
After New Hampshire, he needs to beat Romney in Michigan and Huckabee in South Carolina, and he needs the Republican base, who hates his guts, to do it. Either the base comes to its senses and propels McCain to the nomination, or they engage Huckabee and Romney in a drawn-out, dirty cage fight that lasts till summer and leaves the survivor in no shape to prevail against the Democratic nominee.