Gingrich is working to avoid the fate of some of his rivals, who surged in the polls only to plummet after weak debate performances or other self-inflicted errors. Herman Cain, the former chief executive officer of Godfather's Pizza who is facing sexual misconduct allegations, has been the latest victim of that boom-bust cycle. A Nov. 14 CNN poll found that Cain's support among Republicans fell to 14 percent from 25 percent in October.

Cain Reassessing Candidacy

A new accusation this week that Cain was involved in a sporadic, 13-year affair prompted the Atlanta businessman to announce that he is reassessing his candidacy, a move that could benefit a rising Gingrich.

Evidence of the former speaker's revival since June, when more than a dozen top advisers quit citing disputes over campaign strategy, is growing.

Some aides who remained, such as Hammond, had resorted to sleeping in supporters' homes, bunking together above garages or in spare bedrooms, when fundraising slowed to a trickle in the summer. As of Sept. 30, Gingrich was $1.2 million in debt, according to campaign disclosure reports.

South Carolina Offices

Today, the Gingrich campaign has 10 paid staff and has opened five offices in South Carolina. In New Hampshire, six aides are working out of a new office in the center of downtown Manchester. And in Iowa, Craig Schoenfeld and Katie Koberg, two of six staffers in the state who resigned on June 9, rejoined the campaign mid-November as senior advisers. Hammond has now stayed in enough hotels to earn frequent guest status with Marriott Hotels.

"We first started going across the state in early September," said James Epley, the campaign chairman for Beaufort County, South Carolina. "We've seen it grow from there."

Still, with less than five weeks before the first round of voting in Iowa, some Republicans question whether Gingrich has enough time to build an effective operation.

"The short time frame will make whatever it is less effective," said Jim Dyke, a South Carolina-based Republican strategist. "Highly motivated volunteers can trump a lot of things -- just not time."