8 p.m. ET on CNN. The last remaining obstacle to Romney running the table is Gingrich’s last-minute surge in South Carolina, so yes, this is in fact the most important debate of the campaign. Now that Perry’s out, it’ll also be the debate with the fewest participants, which means extra time for answers and bloodsport. Three questions. One: Will Gingrich bring up Romney’s offshore investments? The Democrats are already prepping an attack about that, and you know how much Newt’s campaign enjoys borrowing Democratic talking points about Bain — whether they’re fair or not. Two: Who does Santorum attack? Newt is his big problem in consolidating the conservative vote, but unless Newt implodes over the next 36 hours (always possible but not probable), there’s no chance Santorum will vault into contention in SC. If he spends the debate tearing Gingrich down, all he’s really doing is helping to carry Romney over the finish line.

Three: How much time, if any, will be spent on Gingrich’s ex claiming he wanted an “open marriage”? And if it does come up, how aggressive will/can Newt be in pushing back against her? Via Matt Lewis, this tidbit from today’s New York Post is intriguing:

In 1995, when Vanity Fair magazine asked Marianne what would happen if Newt ran for president, she boasted she could derail the bid with a single TV interview.

“He can’t do it without me,” she said.

“I told him if I’m not in agreement, fine, it’s easy.

“I just go on the air the next day, and I undermine everything . . . I don’t want him to be president, and I don’t think he should be.”

Was she … joking? She said that to Vanity Fair three years before she found out about Newt’s affair, so it wasn’t an embittered reaction to his infidelity. Follow the link to Lewis’s post and see what his source has to say about it. Also, according to the AP, Newt wasn’t the only party to the marriage capable of making devastating announcements over the phone:

Documents related to the divorce filed Friday in Cobb County Superior Court include a separation agreement signed by the couple and notarized in December 1987. There is no indication it was ever filed.

Browning said Marianne Gingrich called her husband on his birthday in June 1987 to tell him she was leaving him. Gingrich, he said, came back to Georgia to find his home emptied out.

He’s not going to bring any of that up tonight, obviously. It’s too risky to attack the aggrieved spouse you cheated on, even if she started attacking first, so he’ll leave that to his campaign surrogates. Newt’s message will be (a) that he’s sought forgiveness from God and (b) you should, as always, be more angry at the media than at the Republican they’re reporting on. (For a response to that, watch Jenny Sanford’s appearance on “Hardball” today.) That’s good enough to get Blitzer to back off him, but what about Santorum and Romney?

Here’s the Hot Air/Townhall Twitter widget. If you missed it earlier, go read Bill Kristol’s tongue-in-cheek imagining of Mitch Daniels’s SOTU rebuttal next week. The dream of a late entrant to wake us from this Kafkaesque primary nightmare shall never die. Exit quotation for Daniels, Paul Ryan, Chris Christie, and Bobby Jindal: “Vada a bordo, cazzo.”