Since his victory in South Carolina, it has been rough sledding for Newt Gingrich. He gave a lackluster victory speech, then a lackluster debate performance. He’s been on the defensive on his Freddie Mac influence peddling and his speakership. He whimpered about the debate ground rules, which could prevent him from getting a boost from his cheering section. Conservatives have begun stepping forward to loudly rebuff the notion that he’s been a consistent conservative. Andrew Kaczynski followed up with this addition to the “undermine conservatism” chronicles: “In 1988, he warned George H. W. Bush not to run as ‘a continuation of Reaganism.’”

And then yesterday Gingrich got the second of two tongue-lashings from Sen. Marco Rubio (R-Fla.), got slapped down by free-market conservatives for carping about Mitt Romney’s earnings from capital gains and was ridiculed unmercifully for suggesting he’d put a colony on the moon by the end of his second term (neither is happening) and make it a state, to boot. And to top it off, he tried lamely to argue that his adultery was different from Bill Clinton’s behavior, so he wasn’t a hypocrite for condemning the president while carrying on with Callista.

In short, he’s lived up to his reputation as erratic, egomaniacal and incendiary. Better than his opponents could have done, he’s shown the penchant for evasion and self-delusion. He is his own worst character witness.

But when there is a debate for Gingrich there is always the chance to grandstand for the base. Or has that card been played once too often? As Mona Charen writes, smarter conservatives are onto his game: “Newt Gingrich is not your average flimflam artist. He is profoundly, fundamentally, transformationally different. With equal passion, and within 36 hours, he can condemn the media for impugning free enterprise and then (in a huge gift to the Obama campaign) slam private equity and venture capital as ‘rich people figuring out clever legal ways to loot a company.’ There is no concern for intellectual consistency, party loyalty, or the advancement of an agenda. He will condemn Paul Ryan one day and film a global warming commercial with Nancy Pelosi the next — more a loose popgun than a loose cannon.”

Presumably, CNN does not want to be be made to look like a Gingrich super PAC once again, so Wolf Blitzer may avoid serving up any giant beachballs for Gingrich to bat into the crowd. Indeed, another Gingrich outburst may prompt some guffaws from his opponents and a reminder to the audience that they are selecting a nominee and not a radio talk show host. (If ever there were a time to invoke Ronald Reagan’s “there he goes again,” this would be it.) However, Blitzer might ask Gingrich why, as part of his theatrics in the last debate, he lied to John King in yet another attempt to transform himself from perpetrator to victim. ( “After nearly a week on the defensive, CNN’s John King reports tonight that Newt Gingrich’s claim about offering witnesses to ABC News in his defense — to rebut the network’s interview with his second wife, Marianne Gingrich — was not true.”)

As Emmet Tyrell Jr. noted, Gingrich’s gamesmanship is just a tad too transparent:

Now he has found his key for hustling the conservative electorate. He is playing the “liberal media” card and saying he embodies conservative values. Like Bill [Clinton], with his credulous fans, Newt is hoping conservatives suffer amnesia. Possibly some do. Perhaps they cannot recall mere months ago when this insufferable whiz kid was lambasting the great Congressman Paul Ryan for “right-wing social engineering” — more evidence of Newt’s not-so-hidden longing for the approval of the liberal media.

If Gingrich is unable to create another ruckus with Blitzer, he’ll no doubt be pressed to answer tough questions on Rubio’s rebukes, his moon plan (when he lectures the moderator and opponents about his “state in space,” the appropriate response would be laughter) and his attacks on capital gains. He’ll try to brush this off as media-driven babble or strike out at Romney. But this is all about him — his own record, his own ideological flirtations and his own character. And if the moderator or his opponents are sharp enough, he’ll have to defend his wholly irresponsible Social Security schemes.

For Romney, this is a chance to show the last debate was no fluke. He will be helped by a full-throated defense of capitalism and an indictment of the alternative — crony capitalism, which is personified by Solyndra but also by Freddie Mac. He will need to show he has the moxie and the background to take on President Obama’s flawed economic vision. And he’d be wise to explain why his own entitlement and spending reform plans are specific and credible enough to contrast with the president’s non-leadership.

As for Rick Santorum, he’d be smart to stress that while Gingrich was bouncing around like a ping-pong ball in a wind machine on Iraq, he stood four-square behind President George W. Bush and the surge, even at the cost of his own seat. Santorum is a far more sober and consistent conservative than Gingrich and stands to gain the most should Gingrich begin to implode. By taking on Gingrich’s crazy schemes (janitors in schools, men on the moon, etc.) and hammering away at his past support for the individual mandate and TARP, Santorum can try to reestablish his own standing as the most viable not- Romney in the race.

In short, if Gingrich fails to disrupt the proceedings once again with a media-bashing floor show and his opponents continue to pound away as they did on Monday, Gingrich may find it difficult to build on his South Carolina win. That would actually be par for the course in a race in which one state’s election has virtually no impact on the next.