Jordan raised an interesting comparison. Goldwater was the principled guy who couldn’t win but built a movement. Newt is the unprincipled guy who can’t win and might just smash that same movement.

Mitt Romney drew some blood from Newt last night, but I would say Newt came out ahead. Mitt was long on reasons not to trust the former Speaker, short on reasons to support the millionaire from Massachusetts instead. If you were a Florida Republican, you might have more reservations now about Newt’s lobbying and the dismal end of his days in the House. But between the top two he still seems like the one with all the brains and personality. Romney seemed to shrink back to the stature he possessed in 2008. This looked a lot like the Mitt who was on pace to fall behind Huckabee in the delegate count when he dropped out early that February.

Newt’s surge has Michael Steele and other Republican insiders raising the possibility of a brokered convention. (Steele puts the odds, rather implausibly, at 50 percent.) Could the Republican convention be thrown open and nominate… Mitch Daniels? Jeb Bush? Chris Christie? Nate Silver doesn’t rule it out:

Late-entry candidates and brokered conventions have not occurred in the recent past. But there has also not been a case in the recent past in which a candidate like Mr. Gingrich, so vehemently opposed by party elites, was surging ahead in key national and state polls at this stage of the nomination process.

I have my doubts: I wonder whether the GOP establishment wouldn’t rather see Newt go down in flames than waste political capital on a last-minute bid to nominate someone new. What would voters think of being stuck with a candidate for whom none of them had cast their ballots? Mitch Daniels doesn’t have the name recognition or grassroots appeal to match his media hype, and if he declined to run on his own terms, why would he consent to be drafted in a salvage situation?  Another Bush would bring back memories of he-who-must-not-be-mentioned-in-GOP-debates. Christie is more colorful and better known than Daniels — almost certainly too colorful for the party elites and general election voters.

But if Romney loses Florida, the GOP will be rushing headlong into uncharted territory. Note, by the way, the enormous role that SuperPACs have played in undercutting Romney’s fundraising advantage. I could see the GOP letting Newt go down in his blaze in infamy this November, then setting to work rejiggering the campaign-finance laws to make sure it never happens again.

(Here, by the way, is 1980s Newt owning up to having been a Nelson Rockefeller supporter. Last night he talked about attending a Goldwater organizing meeting in ’64 — not an explicit contradiction, but not exactly honest, either.)