By Jeff Mason
WATERLOO, Iowa (Reuters) - Presidential hopeful Newt Gingrich pledged on Sunday to stay in the race for the Republican nomination regardless of the results of this week's caucuses in Iowa where he is dropping dramatically in opinion polls.
Gingrich, who was the top candidate in the state only weeks ago, has taken a tumble after a barrage of negative-themed ads funded primarily by groups that support rival Mitt Romney, the former Massachusetts governor.
The former speaker of the House of Representatives is now polling around fourth place in Iowa, the first state to hold a nominating contest in the run-up to the November election in which Republicans will try to unseat President Barack Obama.
Asked in a Reuters interview whether coming in fourth or lower on Tuesday would make him consider dropping out, Gingrich said, "No."
Survival alone would be a victory, he said, after the ads dented his momentum and his standing in the national race.
"I think the fact that we have survived 45 percent of all the ads in the state being negative about me is already a victory," Gingrich said in an interview on his campaign bus.
"I think there's a surge in our direction right now and I would say we will do respectably despite all the effort, particularly by Romney, to drive us out of the race."
Gingrich, whose campaign has earned a reputation for disorganization, said he had enough campaign funds to propel him through New Hampshire and on to South Carolina, the next two states that hold nominating contests.
"By the time we get to South Carolina, it will be very clear the gap between a Massachusetts moderate who hides his record behind negative ads and a conservative who's talking about positive ideas," Gingrich said.
His campaign raised more than $9 million in the fourth quarter of 2011, putting it in line with similar fundraising by 2008 Republican presidential nominee Senator John McCain four years ago. Gingrich said he did not expect a drop in fundraising after Iowa and predicted Romney would have more trouble attracting donors than he would.
"I think as major donors in this country realize how much Mitt Romney's not going to defend them and not going to protect them and not going to help them, that he will face a lot bigger challenge than I will," Gingrich said.
Gingrich has pledged to make clearer contrasts between himself and Romney, and showed signs of a sharpening attack line, despite his pledge to keep a positive tone.
"It's very hard to be a Massachusetts moderate pretending to be a conservative because people aren't that stupid," he said. "It's very hard to run $3.5 million of negative ads and pretend it's not yours and not have people think you're being dishonest. And I think that all comes across as just disingenuous."
While playing down the effects of a fourth-place or lower finish in Iowa, Gingrich is trying to raise expectations for Romney in New Hampshire, where Romney leads polls.
"If he can't win New Hampshire by a huge margin, there's something really wrong about his position."
Gingrich scoffed at the suggestion a Romney win in Iowa and New Hampshire would mean he had locked up the race.
"I think that's about as dumb as the people who said last summer that I was dead," Gingrich said, referring to speculation
his campaign would end after a staff exodus last year.
"If (Romney) wins Iowa and New Hampshire, South Carolina and Florida, then he locks it up. But I think it's very unlikely he's going to win all four."
Romney has run on his success as a manager and a businessman, potentially appealing attributes as the country faces high unemployment and a stagnant economy, but Gingrich said the former governor lacked experience in reforming the U.S. government.
"If you want to manage the decay, I think Mitt would be fine," Gingrich said. "But I think there's no, no experience at all in his background that would suggest to you that Mitt could turn Washington around."
(Reporting By Jeff Mason, Editing by Alistair Bell and Peter Cooney)