Usually they don’t force the Christian to shake hands with the lion. (AP Photo/David Goldman) (David Goldman/AP)

This debate was fun to watch for exactly the same reason the Ancient Romans enjoyed watching Christians being fed to lions. Tonight, Santorum and Gingrich traded off lion duty, while Romney played the unfortunate believer.

Thursday night, Newt Gingrich proved that there’s a reason his entire campaign can be summed up in the phrase, “I can beat Barack Obama in a debate.”

To say that he had the South Carolina audience eating out of the palm of his hand would be an understatement. During the commercial breaks, I worried that they would rush the stage and offer to bear his children.

Who would have thought that reports of Newt wanting an open marriage would actively help his campaign?

John King made the mistake of beginning the debate by asking Newt Gingrich whether he’d like to address his ex-wife’s news about his asking for an open marriage.

“No,” Gingrich said, and the crowd was his.

“I am appalled that you would begin a presidential debate — ”

The whole hall was engulfed in enthusiastic shouting. They stood. They applauded. Gingrich called it “as close to despicable as anything I can imagine,” and they applauded more.

After that they were pretty solidly in his pocket. John King noted that the offending interview was on another network and the crowd lit torches and grabbed up their pitchforks and closed in. “Don’t try to blame somebody else,” Gingrich said.

“And it’s false,” he added.

For the rest of the evening, he dominated, pausing occasionally so that Rick Santorum could kick Mitt Romney in the vitals.

Romney seemed dazed and confused. He had the general demeanor of someone on whom the plans had been suddenly changed. “Now, guys,” his manner implied, “I thought we’d agreed this wasn’t going to happen.” One was reminded of those people who showed up with picnic baskets to the battle of Bull Run. Except that some of them survived unbloodied.

This was not Romney’s day. First Rick Perry endorsed Newt Gingrich. Then he lost Iowa to Rick Santorum. And then that Marianne Gingrich interview forced him to contemplate Newt Gingrich’s sex life, never an appealing prospect.

And on top of it, the debate, where everyone piled on and drubbed him and did everything short of eating him alive and shouting “ARE YOU NOT ENTERTAINED?”

Santorum pointed out all the objections to Romney that Everyday Voters have, and Romney appeared stunned, as though he had never heard them before. Can’t make a credible case against Obamacare? Governed Massachusetts?

The crowd circled, smelling blood.

Santorum seemed enthused by being at one of the outer podiums again, an environment to which he had become accustomed.

And Romney staggered into every blow, at one point making the strategic error of trying to take on Santorum’s record on abortion. Good luck with that. If it were possible to legislate protection for the twinkle in Daddy’s eye, Santorum would have tried to pass it.

It was as though Romney was doing some sort of strange tribute to Perry’s debate memory. Perhaps he was possessed by Perry’s restive spirit. There had to be some explanation. He couldn’t even parry the question of when he’d release his income tax returns. Why not see last year’s? “Because I want to make sure that I beat President Obama,” Romney said, in one of those cringe-inducing moments that will probably come back tomorrow as a Gingrich ad.

The ability of Santorum to disappear in crowds came up repeatedly for comment. “I was there, too!” he kept pointing out. During the Newt years! At breakfast, Newt! During all the other debates! But Santorum, for the most part, made himself hard to ignore.

And he did a great impression of a rabid pit bull going in for the kill.

He launched a blistering attack on Romney about health care, accompanied by a mildly blistering attack on Gingrich, then came back around for a better attack on Newt Gingrich — “Grandiosity has never been a problem with Newt Gingrich,” he noted, acidly.

Gingrich managed to survive by embracing his own grandiosity — “I think grandiose thoughts,” he noted. A sign of how obviously infatuated with him the crowd was is the fact that no one even tittered at this.

Then Gingrich and Santorum seemed to sense that things had been a little too interesting for the average viewer, so they fought over some inside baseball Beltway scandals from twenty years ago and everyone checked e-mail.

Ron Paul performed well — or rather, he talked occasionally, and Ron Paul supporters applauded, which was about the same thing — and whenever the debate gave signs of consigning him to his place in the corner, the crowd grew restive. Asked if he’d change anything, he suggested that maybe he should speak a little slower.

But the story of the debate was Romney.

At the end of the debate, Dr. Paul needed all his training to attend to Mitt, now faint from loss of blood and raving about tax returns and Barack Obama.

As if Barack were his biggest problem right now.

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