Newt Gingrich strolled onto the campus of Furman University in Greenville eight hours ahead of Saturday’s Republican debate looking very pleased. A campaign that once seemed to have passed him by has come full circle. Can he take advantage of an opportunity that almost no one, except the former speaker, might have expected?

The Republican presidential race is at an inflection point. Businessman Herman Cain is on the defensive, defying political gravity but wounded by allegations of sexual harassment and questions about his readiness to be president. Texas Gov. Rick Perry is in even worse shape, struggling to overcome multiple problems that go well beyond his embarrassing meltdown at Wednesday’s debate in Michigan.

All that has left former Massachusetts governor Mitt Romney an even more apparent front-runner for the party’s nomination, despite the lack of enthusiasm for him among many Republican voters.

Gingrich is rising now in the polls, closer to the top than he has been since his campaign was given up for dead in early summer. And he clearly believes he is the one, perhaps the only one, who can take the crown away before Romney plants it on his head. To do that will test the sometimes volatile and often undisciplined Gingrich to the limits. In the past, he has often been his own worst enemy. Will this time be different?

The man of the moment appeared utterly at ease as he signed autographs and posed for pictures with people on the Furman campus amid football tailgaters on a beautiful fall weekend. He jokingly explained that he has no need to attack Romney. So many in the party aren’t with Romney at this point, he said, that all he needs to do is get most of them, not try to take people away from the former governor.

Instead of attacking Romney, he damned him with faint praise, recounting a recent interview in which a reporter asked him when he was going to take off the gloves against Romney. Gingrich said he told the reporter he had no need to do that.

“I like Mitt, he’s a very good manager,” he said. “I think if what people believe they want is somebody to better manage Washington, D.C., he will be a fine candidate. If they want somebody who can change Washington, I would be a much better candidate.”

Given an opportunity on Saturday night, in a debate at Wofford College hosted by CBS News and National Journal, to expand on those comments, Gingrich declined. “No,” he said, with uncharacteristic brevity. That reflects the posture he has chosen in the nomination contest. Rather than attack his rivals, he is auditioning to lead the attack on President Obama.

If Republicans are looking for a nominee who will go on the attack against Obama, no other candidate has honed those lines quite the way Gingrich has. Just as he condemned the Democrats as the party of the “corrupt, liberal welfare state” two decades ago, he calls Obama a 21st century embodiment of those values.

“We have in the White House,” he said before the debate, “a legitimate, genuine, Saul Alinsky radical who believes in class warfare and bureaucratic socialism.” He paused as if to offer some context to soften that description. “I think it’s wrong,” he said, “but it is a legitimate belief system.” Then he turned back to the attack. “He’s also a disaster in practical terms, with 9 percent unemployment, $2 trillion in debt, a decaying foreign policy.”

Gingrich dreams of Lincoln-Douglas style debates in a general election campaign against the president. If Obama will not agree to three-hour debates, he tells audiences, he will follow the president from city to city and rebut anything said. Here is how he says they would go:

“I will represent American exceptionalism, the work ethic, free enterprise, paychecks. He will represent food stamps, class warfare, bureaucratic socialism.” Nothing would be better for the country than these debates, he says. “It will be a wonderful historic moment for America to make a decision.”

No one relishes debates more than Gingrich. Running an underfunded and idiosyncratic campaign, of which he is the chief architect and implementer, he is dependent on the debates to project himself as a candidate capable of going toe-to-toe with the president next year and as the most knowledgeable Republican in the field.

Gingrich said before Saturday’s debate that a forum focused on national security and foreign policy played more to his experience than any of his rivals, and he was much more the center of attention than he has been in previous debates. He easily fielded questions about Iran, Pakistan, foreign aid and others. He was generous to Romney. His rivals sometimes deferred to him. He also avoided what has been a staple of his performances in past debates, which is attacking the reporters asking the questions.

Gingrich’s other weakness has been a desire not just to show what he knows but to say to people he knows more than anyone else. He kept that instinct in check Saturday night, but he wasn’t able to do so Wednesday in Michigan. When the candidates were asked to explain how they would reform health care and were given 30 seconds, he called the question “absurd.” Challenged by the moderator, CNBC’s Maria Bartiromo, his response included references to a book he had written and a think tank he had founded.

That is the other Gingrich, the one that still stands in the way of his hopes of becoming the alternative to Romney and of defeating him for the nomination. He not only relishes debates, he delights in over-the-top rhetoric, stridency, extravagant criticism and condescension toward his enemies. He becomes a scold.

Gingrich has various attributes, which have kept him as a prominent voice in the Republican Party for more than two decades in spite of setbacks and self-inflicted wounds. For reasons mostly beyond his doing, he may have been handed a new opportunity for redemption and leadership. Whether he can restrain the impulses that have brought him down in the past will now be his biggest challenge.