There are a lot of Republican voters in South Carolina who told pollsters and reporters that they voted for Newt Gingrich because they believed he would defeat Barack Obama by humiliating him in debates.

I know the look many of them have on their faces tonight. It’s the same look that House Republicans had on their faces at about this point in 1996, after a year of following Newt because they thought he had a legislative plan for defeating Bill Clinton. South Carolina Republicans are lucky; the snake oil they purchased isn’t going to be around much longer. House Republicans had to put up with Newt’s “leadership” for three more years.

Yes, for the second time this week, Newt showed that his debate skills are massively overrated, particularly his ability to attack an opponent with clear vulnerabilities. And Mitt Romney demonstrated exactly how to go about carving up an overmatched opponent. This time, not even having a noisy audience to appeal to could save the former Speaker. Several times over the course of the debate, Romney hit Newt hard, and Newt sputtered around and couldn’t find an effective response. On immigration, on Freddie Mac and on Romney’s investments, Newt couldn’t find an exchange that worked for him. The final blow was a long (long, long) segment about space, and Newt’s easily-mocked plan for a lunar colony, which Romney effectively dismissed — and called Gingrich out on pandering to the narrow interests of each state they’ve competed in. It’s sometimes hard to read how these things play to voters, but I thought it all combined to be pretty devastating. Intrade agreed: Newt’s chances of winning the nomination according to the bettors there went from about 10% down to around 3% over the course of the debate. Regular readers know I feel that’s still too high.

Still, Barack Obama’s team can’t be too disappointed. For example: Newt swung wildly at Romney, accusing him of supporting Freddie Mac and Fannie Mae through stock ownership. Romney got the better of the discussion because Newt’s position is untenable — being a major consultant to Freddie’s lobbying shop just isn’t going to play in a Republican primary this year. But Romney wound up deflecting accusations about his investments by talking about his blind trust, and in other ways playing right into stereotypes of a rich, out-of-touch plutocrat. That Gingrich isn’t able to exploit that weakness in a debate is interesting for this week in Florida, but the issue isn’t going away. Nor is the fact, as Rick Santorum pointed out late in the debate, that Romneycare does make it difficult for Mitt Romney to attack ACA as effectively as other candidates might.

Santorum, by the way, had a good night. It just seems unlikely, at this point, that he can rally to even a close second in Florida, and even then it’s hard to see him actually winning the nomination at this point, although it would probably earn him enough resources to compete on for a while. Ron Paul was also there, doing what Ron Paul does; it still doesn’t really matter to the question of the nomination.

But the winner tonight was clearly Mitt Romney, and that makes him a solid favorite to win in Florida on Tuesday.

More PostOpinions on the Florida debate

Meyerson: Romney’s night to shine

Rogers: Solid Romney vs. big Gingrich

Rubin: Gingrich wipes out

Eskew: The real winner — Obama