After disappointing showings in both Iowa and New Hampshire, it appeared that Newt Gingrich’s presidential campaign was about to hit bottom. But improbably, Gingrich has rebounded, and with a new poll showing him holding a small lead over Mitt Romney in South Carolina, it appears that he may be riding one more surge back into contention.

The latest Insider Advantage/Majority Opinion Research poll conducted for the Augusta Chronicle and The Savannah Morning News shows Gingrich holding a 32-29 percent lead over the frontrunner. That’s a reversal of the same poll’s showings published on Sunday that had Romney leading 32-21 percent. Other polls still show Romney ahead — including a Politico/Tarance poll also published yesterday that has him up by seven points. But there’s little question that Gingrich’s strong performance in Monday night’s debate and the accumulated impact of the attacks on Romney has put the former speaker in a position to put the outcome of the GOP race in doubt with a victory in South Carolina on Saturday. It may also bring him closer to the one-on-one matchup with Romney that he and other conservatives have always thought was the only way to defeat him.

Gingrich’s surge is the product in no small measure of the failure of his conservative rivals. Rick Santorum has not capitalized on what turned out to be a victory for him in Iowa and finds himself now losing ground in South Carolina with both of the most recent polls showing him barely breaking into double digits. Also crucial was the collapse of Rick Perry’s campaign, which ended today with the Texas governor endorsing Gingrich.

Though Santorum is giving every indication he will not pull out after South Carolina no matter what the outcome, his seeming fade out does allow Gingrich to portray himself as the one viable conservative alternative to Romney. Since the latter’s rise to frontrunner status has been more the product of a split conservative field than any great outpouring of enthusiasm for the former Massachusetts governor, it’s fair to say a Gingrich victory in South Carolina could alter the entire dynamic of the race.

Throughout the race Gingrich has benefitted from the many televised GOP debates that have highlighted his rhetorical gifts. Though Romney hasn’t done badly, he cannot match Gingrich’s ability to rally the GOP faithful with stirring rebukes of the media or appeals to Reaganesque critiques of the welfare state. Another such triumph tonight in the last debate before South Carolinians vote could be decisive.

But like the other improbable Gingrich surge in November and December which put him briefly at the top of the Republican heap, his current bubble has the potential to burst at any moment.

The assumption that most Republicans would prefer any conservative alternative to Romney is about to be put to the test. Though the focus on Romney’s business record and tax returns this week have put him on the defensive, if Gingrich is able to climb back into contention, the public’s attention will be focused again on his record. And for a man with as much political and personal baggage as Gingrich, that is never a good thing.

Along those lines, tonight’s ABC “Nightline” interview with Gingrich’s second wife Marianne may strike many Republicans as unfairly timed, coming as it does less than 48 hours before a primary election that might decide Gingrich’s fate. But though this show will produce the usual backlash against the media that always occurs anytime a Republican is put under the microscope, it will also be a reminder of all the nasty bits in his biography that helped sink the last Gingrich surge in December.

Nevertheless, it must be acknowledged that Perry’s pullout and Santorum’s collapse puts Gingrich in position this weekend to demolish the notion that Romney’s nomination is inevitable. If the majority of conservatives jump on the Gingrich bandwagon, that should be the formula for victory in South Carolina. But the downside of raised expectations there is if Romney does hold on and emerge the victor, the deflation of this latest Gingrich bubble may soon follow.