Something to whet your appetite for tonight’s Thunderdome debate. Could Newtmentum really have shot him to a six-point lead after he trailed Romney by double digits just a few days ago? Note that PPP’s data comes from a one-day snapshot, which means a smaller-than-usual sample, which in turn means a larger-than-usual margin of error of five points. Newt’s may very well be leading right now, but … by six?

Even so, as I write this, InTrade gives him a 42.5 percent chance of winning on Saturday. After Perry’s endorsement, Palin’s quasi-endorsement, and Santorum’s fade, who wants to bet against him?

This is not a case of Romney imploding. His support has been pretty steady in the 28-30% range in our South Carolina polling so far. But Gingrich has risen from 23% to 34% over the last two weeks, benefiting from declining support for Santorum and also from undecided voters moving into his camp.

It’s clear that the debate Monday night did a lot to help Gingrich’s prospects in the state. 56% of voters say they watched it, and with those folks Gingrich’s lead over Romney is 43-27. Romney still has a 29-22 advantage on Gingrich with those who didn’t tune in.

Gingrich is starting to consolidate his support with some of the more conservative parts of the South Carolina electorate. He has a 50-18 advantage on Romney with Tea Party voters. He’s up 39-23 with those describing themselves as ‘very conservative.’ And he even has a 37-20 advantage with evangelicals.

Perry’s supporters actually divide fairly evenly among the rest of the field when you ask them who their second choice is. Maybe his endorsement today will change that, but even if it doesn’t, it’s useful to Newt as further evidence that he’s the anointed Not Romney in the field, not Santorum. If Santorum finishes a distant third or even fourth this weekend, the commentariat will be all over him next week to drop out and then maybe Florida will become interesting. I still think Romney wins there because he’s the only one with the money and organization to play hard, but what happens if Newt has another stellar debate tonight and shocks the world with a landslide on Saturday? Romney can handle finishing second in SC, but if he gets blown out the media will go nuts with stories about a resounding rejection from the southern base and his mystique of inevitability being shattered. For now, at least, Team Mitt is putting on a brave face:

“South Carolina is like Iowa — an opportunity that we never thought we would get,” [a Romney campaign] source said. “If you dust Newt up there so that Santorum stays alive, Newt gets no traction heading into Florida, where he has no structure, and then into a month, February, where there is no obvious good state. Points fell off Newt fast when voters were reminded of his entirety, not just his facility as a debate presence.”

The source said the Romney campaign’s goal in South Carolina remains the 34 percent John McCain won here in 2008, which the campaign estimates will be enough to win, so long as conservatives don’t consolidate around either Gingrich or Santorum. And the campaign is not worried about Santorum.

That was published yesterday afternoon. There’s been a fair amount of consolidation in the 27 hours since — 100 tea-party leaders from 25 states are reportedly set to endorse Newt today — and there may be more to come tonight depending upon how things go on CNN. Good to know that we finally have an a Not Romney. Too bad it’s a guy who was famously unpopular the last time he held major public office, who couldn’t pull it together enough to get on the ballot in his home state, who’s flirted with the individual mandate and cap-and-trade, and whose penchant for loose-cannon grand pronouncements is guaranteed to generates oodles of “unhelpful” news cycles if he’s the nominee. Come next week, your choice will be between him, Captain Flipflop, and Ron Paul. Worst field ever. Ever.