The unorthodoxy of Newt Gingrich’s presidential campaign will either make or break him, and it will happen in Iowa, where he is bleeding support under a hail of harsh TV advertising from opponents and their allies.

Gingrich’s answer to the barrage has been to try to stay “nice.” It’s a strategy that not only defies the former House speaker’s instinct for combat but also is producing uncertain results as it is pitted against the proven effectiveness of negative ads — particularly the millions of dollars’ worth that are piping through Iowa televisions in these final two weeks before the Jan. 3 caucuses.

Staying positive is not the only way in which Gingrich is following an unconventional script. Until this month, Gingrich’s campaign staff featured virtually no one who had worked on a presidential campaign.

The candidate expresses his disdain for paid consultants every chance he gets. He celebrates the young man from Topeka who runs the candidate’s Twitter feeds from the counter of his father’s auto-repair shop — and the social-media executive from California who moonlights in charge of Gingrich’s Facebook page.

Most of all, Gingrich relies on his own instinct, an almost religious faith that — even without a traditional campaign operation — his knowledge, experience and way with words will carry the day.

The danger for him is taking it too far.

‘I need your help’

Gingrich’s resolve to fight the Iowa advertising onslaught by staying positive puts that confidence on vivid display even as it displays the risks. The approach dominated his appearances during a three-day swing through Iowa this week and steered him away from his message of bringing years of conservative leadership to the tasks of fixing the economy and Washington.

“I want to do this based on positive ideas, not on negative campaigning, and I need your help to make that work,” Gingrich told a crowd of about 100 supporters at the Swamp Fox Pub here this week. “If somebody wanted to create ‘Iowans for a Positive Campaign,’ I think the number of people who would join it overnight would be amazing.”

The displays have made his aides increasingly nervous and prompted some to urge him to get back on script. But Gingrich is doing what he thinks he has to do to survive. His campaign shot to the top of the polls last month after spending much of the year at the back of the pack. He and an independent committee supporting him are playing catch-up to build the organization and raise the money they need to stand up to the assault. Meanwhile, a series of public polls show Gingrich’s position slipping in the midst of the barrage of ads.

The attacks have flooded the airwaves in ads paid for by the campaigns of Texas Gov. Rick Perry and Rep. Ron Paul (Tex.), as well as an independent super PAC supporting former Massachusetts governor Mitt Romney. Among the topics: Gingrich’s acceptance of $1.6 million in payment from federally backed mortgage giant Freddie Mac; his support for taxpayer funding of “some abortions”; and the ethics investigation of him when he was speaker about his use of tax-exempt funds for a partisan educational program.

Gingrich has pushed back hard against the charges, which he says are untrue. After a town hall at a heavy-equipment plant in Ottumwa this week, he held a lengthy news conference in which he called upon his chief rival, Romney, to publicly repudiate the ads being aired by “Restore Our Future,” an independent committee run by Romney’s supporters. Romney has declined to do so, arguing that the law prohibits him from communicating with the independent group.

Gingrich fights back

A few times, Gingrich’s resolve to stay positive has crumbled.

In New Hampshire last week, he lashed back at Romney’s call for him to return his pay from Freddie Mac by describing the “millions” Romney earned “bankrupting companies” and laying off workers while a businessman at Bain Capital. This week in Iowa, Gingrich called Romney “purely dishonest” for saying that he couldn’t stop the independent PAC from running negative ads against him.

Gingrich seemed to revel in the chance to scuffle verbally with Romney. He added flourishes to his argument with each successive campaign stop, as if resorting to a familiar set of behaviors — and offering a potentially damaging reminder to voters of his long history as a combative and partisan House speaker.

Gingrich could be doomed no matter what he does; modern American political history reveals that negative ads work, and whether the response is positive or negative, it’s difficult if not impossible to compete with the volume of attacks coming down on Gingrich.

“Negative still works pretty well,” said Democratic consultant Joe Trippi, who watched his client in 2004, former Vermont governor Howard Dean, succumb to a similar barrage in Iowa after taking the lead in the race. “You can’t fight it. It’s not enough to push back whether it’s all positive or calling them all liars — [Gingrich] doesn’t have enough up to push against it.”

Emotional appeal to voters

Trippi offered one caveat, however, which is that Gingrich’s long-standing relationship with voters could inoculate him against some of the charges. Additionally, Gingrich is making an emotional appeal that could work in Iowa, where a heavily evangelical Republican electorate may be open to his request for forgiveness regarding some of the “baggage” that his opponents are pointing out in detail.

“Every Sunday, I preach that we’re all born into sin,” said Jim Stogdill, pastor of Messiah Lutheran Church in Johnston, Iowa, outside Des Moines. “That makes us all equal. So if that’s the case, and we’re going to apply that to this race, then why is this such a big deal? Either they don’t understand forgiveness or they’re not Christian. It’s interesting that Christians who believe in Christ don’t apply that to the people in their everyday lives.”

Stogdill had just listened to J.C. Watts, the former Oklahoma congressman and perhaps most prominent Gingrich supporter, defend his friend over breakfast with a group of pastors. Watts spent two days in Iowa this week meeting with business leaders and pastors and not only making the case that some of the charges are false but also appealing to his audience’s Christian faith in forgiving Gingrich for having made mistakes.

“When people make mistakes you shouldn’t run from them, you run to them,” Watts said. “That’s more the ministry part of me. We tend to kind of seclude ourselves from people that need our help the most, when they’re in the most trouble. And Newt and I, I haven’t always agreed with him, but I never disliked him. We always remained friends.”

Watts added that Gingrich’s opponents — Romney, Perry and Rep. Michele Bachmann (Minn.), for instance — aren’t perfect either. “I could show you flaws in all of them,” he said.

Gingrich is using the “nice” card in other ways. He has pushed his wife, Callista, to play a more active role on the campaign trail, where she has opened up more about her love for music and her Midwestern roots. (She grew up in Wisconsin and attended Luther College in Decorah, Iowa.) The Gingriches also appear in an ad together, in which the candidate prays for “peace and brotherhood.” Already playing on the Internet, the ad will air on TV stations across Iowa on Friday.

Staff writer Karen Tumulty in Washington contributed to this report.