DES MOINES, Iowa — Talking too much about an old friend has been painful for Gordon Austin.

“I have the bruise on my ear to prove it,” said the retired surgeon from Carrollton. He’s here with his wife, Meredith, and 30 other Georgia volunteers, working phone banks, carrying signs — whatever it takes to push Newt Gingrich across the finish line in Tuesday’s Iowa caucuses, the first real votes cast in the 2012 presidential campaign.

Gingrich’s up-and-down candidacy has prompted what may be the largest Georgia invasion of this state since a certain peanut farmer helped create the legend of Iowa’s political clout 35 years ago.

The question is whether this latest Southern incursion will be large enough — and strong enough — to preserve the former Georgia congressman’s recently won status as the predominant obstruction between former Massachusetts Gov. Mitt Romney and an early stampede to the Republican presidential nomination.

Romney and Texas congressman Ron Paul, whom the latest polls tout as the front-runners in Iowa, took a break from the state Saturday. Both are confident of a good showing when tens of thousands of Iowa Republicans gather in living rooms and civic halls to cast their secret ballots.

The other candidates continued to slog it out, including Gingrich — who this weekend has his wife, two daughters and a brace of Atlanta grandchildren in tow.

“No one knows who’s going to decide to turn out. No one knows what the conversations are going to be like at the caucuses. I think that up to half the caucus-goers are going to be potentially willing to switch during the course of the evening, as they talk with each other,” Gingrich told about 150 voters crammed into a coffee shop in Creston, a grain town in the southern hills where the wooden floors still shake when the trains rumble through.

It was late Friday, the final stop of the day. A weary Gingrich had already won the daily headline war with a few tears shed before a group of Republican women, as he talked about his late mother and her struggle with a bipolar disorder.

Presidential campaigns in Iowa are traditionally about the human touch. Gingrich’s damp eyes were cited as proof that the former U.S. House speaker isn’t the ogre that a barrage of negative TV ads here has declared him to be.

Gingrich was his usual sharp-tongued self, but that was something that Jerry and Karla Hynes — he’s a landlord, she works in a bank — were looking for. In 2008, they were Democrats and supporters of Hillary Clinton. This year, they intend to change their party registration and vote in Tuesday’s caucuses.

Jerry Hynes said he appreciates brashness. “I’m looking for someone willing to lose it all to get what he thinks would be good for the nation,” he said.

Gingrich delivered. But in between his declarations to erase the “death tax,” repeal President Barack Obama’s health care overhaul, and revive the conservative legacy of Ronald Reagan, Gingrich renewed his promise that he wouldn’t reply to attacks on his four decades in Washington politics.

The line, which earned him some applause, could come back to haunt him within the next 48 hours.

“This has been a wild and woolly campaign,” Gingrich admitted. Six months ago he was abandoned by his staff and $1 million in debt, so the former congressman has already made one of the more remarkable comebacks in American politics.

Strong performances in a long-running series of televised Republican debates, coupled with the rise and fall of candidate after candidate — first U.S. Rep. Michele Bachmann of Minnesota, then Texas Gov. Rick Perry — helped him. But it was the collapse of Georgia entrepreneur and radio talk show host Herman Cain last month that — for a few ecstatic days — pushed Gingrich to the top of the polls in Iowa.

But ever since, Gingrich has sunk under the weight of a multimillion-dollar TV assault from the Paul campaign and Restore Our Future, a Romney-affiliated “Super PAC” bound by no contribution limits. “More baggage than the airlines,” declares the Restore Our Future ad. The latest polls show Gingrich mired in a fight for third or even fourth place with Perry and former Pennsylvania U.S. Sen. Rick Santorum.

Several groups have stepped up on behalf of Gingrich. On Saturday, Newsmax.com, a conservative news and politics website, began airing a 30-minute “infomercial” in Iowa, in which Michael Reagan, son of the former president, declared Gingrich to be his father’s ideological heir.

For Gingrich, the problem isn’t just being on the short end of an air war. This is a man who, when his campaign prospects looked darkest this summer, vowed that he would use the Internet and social media to dispense with traditional campaigning.

In Iowa, such talk smacks of heresy.

Gingrich’s Iowa headquarters was established only at the tail end of November. The candidate made a first visit there in mid-December. Georgia volunteers began arriving last week.

On Saturday, they mixed with 40 volunteers for a daunting assignment: contacting 6,000 Republican voters by the end of the day — and the year.

John Douglas, a retired Army major from Social Circle, drove two days from Georgia to work for Gingrich here this weekend. Fueled with Diet Coke, Douglas — a former Perry enthusiast — occasionally introduced himself to the Iowa voters on the phone as a former state senator from Georgia. Which he is.

“I had a lady just insult me,” he joked. “She said I didn’t sound too Southern.”

Gingrich’s lean Iowa staff includes seven paid staffers and three offices across the state. Ron Paul, in contrast, has 10 paid staffers. But it’s not just the size that matters. The Romney operation consists of four paid staffers, one consultant and a single campaign office in Des Moines.

Just across the way from Gingrich’s state headquarters, in the same business park in Urbandale, is the headquarters of the surging campaign of Rick Santorum. It has been up and running since June. On Friday, as an NBC poll placed Santorum — for the first time — amid the top GOP candidates, he greeted an unannounced AJC reporter at the door. Such things happen in Iowa.

The same debates that allowed Gingrich to shine obscured the concerns of evangelical voters, said Santorum, who has bet his campaign on the continued strength of blue-collar social conservatives in Iowa. In the last few weeks — coinciding with Gingrich’s decline here — Santorum said he has seen many of those who supported former Arkansas Gov. Mike Huckabee, who won the caucuses in 2008, come to his side.

But there’s another reason for his late charge. When the legacy of Jimmy Carter and his Iowa campaign comes up, Santorum points to his sweater vest. “That’s me,” he said. “I still carry my own bags. We had the whole family here this summer for almost three weeks.”

In 1972, George McGovern was the first candidate to use Iowa’s early voting position as a bridgehead to the nomination. But it was Carter, only four years later, who made an art of face-to-face contact with the rural state’s voters.

Tim Kraft, 71, who coordinated Carter’s Iowa campaign, estimates that 150 Georgians — dubbed the Peanut Brigade — wandered in and out of Iowa in the five months preceding the 1976 caucuses.

“We put a lot of emphasis on local people because we didn’t have enough money for staff,” Kraft said.

“The real Peanut Brigade was the Carter family. They were a constant presence. Rosalynn Carter spent a lot of time in Iowa. She was gold, in terms of making connections and winning people over,” Kraft said.

This isn’t to say that a ground game is everything in Iowa. In December, a poll by the Des Moines Register indicated that 35 percent of GOP voters polled had enjoyed a face-to-face experience with at least one presidential candidate. More voters — 20 percent — had met Bachmann than any other candidate. Current polling has her at the back of the pack.

A disappointing showing by Gingrich on Tuesday won’t be fatal. Already, his campaign is pointing to his potential for rising to the top again — if not in next week’s New Hampshire primary, then later in the month in South Carolina and Florida.

But a drubbing on Tuesday would play into suspicions that Gingrich, while a stellar debater, is weak when it comes to organization — something wickedly underlined by Romney last week. The failure of the Gingrich campaign to win a place on the Virginia primary ballot, Romney said in Iowa, reminded him of “Lucy in the chocolate factory.”

David Yepsen, the retired political columnist for the Des Moines Register, is now the director of the Paul Simon Public Policy Institute at Southern Illinois University Carbondale.

Yepsen said Gingrich’s inability to maintain his top poll position should be a concern to supporters.

“As you rise in the polls, people start hammering back at you. I just don’t have the sense that he had not only the [financial] resources to respond, but the infrastructure to respond,” he said. “You can respect a guy who wants to do it his way, but you also have to respect the rules and rituals of political campaigns — or you lose.”