Not her ability to rev up the right wing -- anyone who's read the comments on Peggy Noonan's latest column knows that the Palinistas are fanatics. But I don't think there are enough fanatics in America to get Palin to the GOP nomination, let alone the White House:

Were Palin actually to secure the 2012 nomination, the result would be a fiasco for the G.O.P. akin to Goldwater 1964, as the most relentless conservative Palin critic, David Frum, has predicted. Or would it? No one thought Richard Nixon — a far less personable commodity than Palin — would come back either after his sour-grapes “last press conference” of 1962. But Democratic divisions and failures gave him his opportunity in 1968. With unemployment approaching 10 percent and a seemingly bottomless war in Afghanistan, you never know, as Palin likes to say, what doors might open.

It’s more likely that she will never get anywhere near the White House, and not just because of her own limitations. The Palinist “real America” is demographically doomed to keep shrinking. But the emotion it represents is disproportionately powerful for its numbers. It’s an anger that Palin enjoyed stoking during her “palling around with terrorists” crusade against Obama on the campaign trail. It’s an anger that’s curdled into self-martyrdom since Inauguration Day.

But would a Palin candidacy resemble Goldwater's 1964 debacle? Maybe -- if the Republicans managed to unite around her. I am not convinced that they would do so. Having Sarah Palin at the top of the ticket would cause unbearable torsion within the party, and would certainly result in the nuttiest political convention the world has ever seen, something like the 700 Club guest-hosted by Glenn Beck. It could well crack the party in two, forcing the minority of moderate and mainstream GOPers out of the party to form their own center-right coalition.

This might sound preposterous, but consider the damage done to the Republican "brand" over the last few years. That brand is not indestructible, and one has to wonder how long the sane people will stay if the truly crazy people gain total control and decide to take the party out in one last blaze of glorious martyrdom.

A Palin candidacy, therefore, might result in a replay of George Wallace's 1968 run. It would be a regional candidacy fueled by everything Wallace exploited - paranoia, class resentment, fear of the future, and a cult of personality built around a single defiant demagogue.

And the Republican dissidents -- let's call them the New Whigs -- would go to their own corner and wait for their chance to pick up the pieces.

There would be a lot of pieces to pick up.