DES MOINES, Iowa (Reuters) - The Democratic White House contenders on Tuesday criticized front-runner Hillary Clinton’s support of a get-tough resolution on Iran, saying it aided President George W. Bush in a reckless march toward war.

Senator Hillary Clinton (D-NY) sits alongside former Senator Mike Gravel (D-AK) and Senator Barack Obama (D-IL) at a Democratic Party Debate conducted on National Public Radio in Des Moines, Iowa, December 4, 2007. REUTERS/Jason Reed

In a debate in Iowa, Clinton’s rivals questioned her Senate vote earlier this year to declare an Iranian military unit a terrorist group and ridiculed her claim it was aimed to bolster an aggressive diplomatic approach.

“Declaring a military group sponsored by the state of Iran a terrorist organization, that’s supposed to be diplomacy?” asked John Edwards, a former North Carolina senator.

Clinton, a New York senator who leads national polls in the Democratic White House race and is locked in a tight three-way struggle in Iowa with Edwards and Illinois Sen. Barack Obama, said the resolution had led to some positive changes in Iran.

“I understand politics, and I understand making outlandish political charges, but this really goes way too far,” she told Edwards.

“If we thought that anything in that resolution gave even a pretense of legitimacy to President Bush taking any action, we wouldn’t have voted that way,” she said.

The exchange came one day after a national intelligence report said Iran had halted its nuclear weapons program in 2003. Clinton and all of the Democrats condemned Bush’s claim on Tuesday that Tehran remained dangerous and nothing had changed despite the report.

“It is absolutely clear that this administration and President Bush continue to not let facts get in the way of his ideology,” Obama said. “And that’s been the problem with their foreign policy generally.”

The debate, the second in four days in Iowa, was broadcast on National Public Radio and came as the race intensified ahead of the January 3 contest that opens the state-by-state battle to choose candidates for the November 2008 general election.

Clinton was the only senator in the race to support the Iranian resolution. Delaware Sen. Joseph Biden and Connecticut Sen. Chris Dodd opposed it, and Obama did not vote because he was campaigning.

A REAL DIVISION

“We have a real division here. I mean, among the Democratic candidates, there’s only one that voted for this resolution. And this is exactly what Bush and Cheney wanted,” Edwards said.

Obama renewed his criticism of Clinton’s vote, one day after she questioned his political courage for skipping it.

“What I’ve been consistent about was that this saber-rattling was a repetition of Iraq, a war I opposed, and that we needed to oppose George Bush again. We can’t keep on giving him the benefit of the doubt, knowing the ways in which they manipulate intelligence,” Obama said.

Biden said the Senate vote and Bush’s subsequent declaration that the Iranian military unit was a terrorist group had been disastrous.

“The moment that declaration was made, oil prices jumped over $18 a barrel. The moment that declaration was made, every one of our friends, from Iraq to Pakistan, felt they had to distance themselves from us because it appears to be a war on Islam,” Biden said.

Former New Mexico Gov. Bill Richardson, who was at a funeral, was the only Democratic contender not to attend.

While the candidates disagreed sharply on Iran, the rest of the two-hour debate focusing on China and immigration featured little of the contentious tone of earlier debates and recent campaign-trail rhetoric.

The Democrats all criticized Bush’s leadership in dealing with the growing economic power of China and the rising U.S. trade deficits with the Asian giant. Edwards said that would be one of the toughest problems for the next president.

“We have not held China accountable, and the result is the loss of American jobs, the struggling of American families, the struggles of the middle class,” Edwards said.

It was the second recent radio-only debate in a White House race, following one by the Democratic contenders in 2004. That was the first on radio alone since Republican primary candidates Harold Stassen and Thomas Dewey met in 1948.

The candidates sat in a small, private room at a V-shaped table facing three moderators, with no audience. Sponsors said the idea was to remove television cameras and allow candidates and voters to concentrate on substance.

(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)