NEW ORLEANS (AP) -- The millions of dollars spent by Mitt Romney's allies on TV ads attacking his two main rivals have helped Romney pull ahead in the GOP presidential race. The resulting bitterness, however, is making it hard for him to lock down the nomination and end the party fighting that delights Democrats.
Republican insiders say Rick Santorum and Newt Gingrich are fuming over the hard-hitting 30-second spots that sent them tumbling after they gained early leads in Iowa, Florida, Michigan and other states.
Every election bruises some feelings. But campaign veterans say Santorum and Gingrich feel the commercials were pointedly unfair, and that's a big reason they keep fighting despite Romney's significant lead in delegates and pleas from some Republican leaders to close ranks and focus on President Barack Obama.
"The Romney folks have run a pretty ugly campaign," said Mike McKenna, a Republican strategist and pollster who is unaffiliated in the presidential race. "It's been very personal, it's been very ugly, it's been very hostile. There's a lot of bad blood."
Santorum and Gingrich, or political action committees that back them, have mounted their own attacks against Romney, of course. But a pro-Romney super PAC, Restore Our Future, has swamped them in fundraising and spending. First it buried Gingrich in an avalanche of attack ads in Iowa and Florida, then it hammered Santorum in Michigan, Ohio and elsewhere.
These committees can spend unlimited money supporting candidates as long as they don't coordinate with the candidates, yet are required to reveal little about who they are.
One or two ads in particular seemed to infuriate them, and their bitter complaints failed to persuade the former Massachusetts governor to demand an end to the ads.
An ad repeatedly aired by the pro-Romney committee claimed that Gingrich had co-sponsored legislation "that would have given $60 million a year to a U.N. program supporting China's brutal one-child policy." The strong implication was that Gingrich, as House speaker, had promoted abortions in China.
The legislation, however, specifically barred U.S. funds from being used for "the performance of involuntary sterilization or abortion or to coerce any person to accept family planning."
Gingrich also is angry over ads saying he paid a $300,000 fine to settle the House ethics case filed against him in the mid-1990s. Gingrich says it was a negotiated reimbursement of the investigation's costs.
Two former House members who support Gingrich recently sent a letter to newspaper publishers and editors saying Romney "chose to run and temporarily profit from blatantly untrue TV spots."
Romney's "negative attack mentality, unfortunately, is a reflection of his own persona," said the letter, which Gingrich's friends eagerly distribute. Romney's Feb. 7 loss of three state contests to Santorum, the letter said, was "widely interpreted as voter rejection of Governor Romney's `scorched earth' campaign tactics."
Santorum has complained often about a pro-Romney ad that accused Santorum of backing legislation to allow felons to vote. Santorum, a former Pennsylvania senator, said he would allow them to vote only after completing their sentences, probation and parole.
In a Jan. 16 debate, Santorum said Romney should demand that the "inaccurate" ad be taken down. Santorum said Romney, when governor, tolerated a more liberal state law, which allowed ex-felons to vote while still on probation or parole.
Romney said violent criminals should never be allowed to vote again. He noted that he has been the target of attack ads, too. He said he had no control over super PACs, which by law must operate independently from official campaigns.
Republican consultant John Feehery said the law gives candidates' "plausible deniability" about the tactics used by super PACs supporting them. "But everybody knows what the game is," Feehery said, "and that's what makes people angry" when the attacks continue. "There are some hard feelings," he said.
Feehery noted that in the 2008 race, Romney's tactics angered rivals Mike Huckabee, Fred Thompson and the eventual nominee, Arizona Sen. John McCain.
"None of those guys liked Romney very much," Feehery said. "There's a history there," he said, although McCain has endorsed and campaigned for Romney this year.
McKenna said Romney, who bought and reorganized companies when he led Bain Capital, talks of "closing the deal," and seems to approach the campaign like a corporate takeover in which GOP delegates are "shareholders."
"In takeovers, you don't care about burning the other guy down because you're never going to see him again," McKenna said. He said Romney seems unaware that "he'll need guys like Gingrich and Santorum not to hate his guts."
Some Republicans say the campaign quarrels are no worse than those between Obama and Hillary Rodham Clinton, which lasted deep into the summer of 2008. McKenna disagrees.
With Obama and Clinton, he said, "it was personal, but just around the edges. This is personal to the core."
Santorum and Gingrich have sizeable egos and ambitions, so it's possible they would be fighting just as hard against Romney if the ads against them had been milder. Whatever the case, both men seem to take pleasure in highlighting Romney's weaknesses, even though it might hurt their party in the fall against Obama.
Gingrich, who's refused to bow out despite losing crucial races this past Tuesday in Mississippi and Alabama, derided Romney's third-place finishes.
"If you're the front-runner and you keep coming in third, you're not much of a front-runner," he told supporters after falling short in the South.
Gingrich faces massive odds. But his speech at least gave him a measure of payback for the withering TV ads that sent him reeling in Iowa, and again in Florida.