MANCHESTER, N.H. — The leading Democratic presidential candidates clashed Sunday over each other's claim to be the true candidate of change in the final hours of the slushy New Hampshire homestretch. Clinton told voters they should elect "a doer, not a talker." Obama countered that his rivals are stuck in the politics of the past.

At a raucous rally in a high school gymnasium in Nashua, Clinton skewered Obama for several votes he has cast in the Senate, such as his vote in favor of the Patriot Act and for energy legislation she described as "Dick Cheney's energy bill." She never mentioned Obama's name but left no doubt about whom she was discussing.

"You campaign in poetry, you govern in prose," Clinton said.

Obama, speaking at a packed Manchester theater, took issue with Clinton's criticism of him during Saturday's Democratic presidential debate.

"One of my opponents said we can't just, you know, offer the American people false hopes about what we can get done," he said.

"The real gamble in this election is to do the same things, with the same folks, playing the same games over and over and over again and somehow expect a different result," he said. "That is a gamble we cannot afford, that is a risk we cannot take. Not this time. Not now. It is time to turn the page."

The rhetoric reflected the potentially pivotal nature of Tuesday's primary. Obama, the freshman Illinois senator, is hoping to sustain momentum from his caucus victory in Iowa, and Clinton is looking to recover from her stinging third-place finish.

A new USA Today-Gallup poll showed Obama opening up a lead at 41 percent, Clinton 28 percent, and John Edwards 19 percent. The New Hampshire poll was taken Friday through Sunday.

One of the sharpest exchanges of the day came when Edwards and the Clinton campaign traded words over Edwards' reference to last month's death of a 17-year-old girl, Nataline Sarkisyan of California, in making his case for challenging the health insurance industry.

Edwards, speaking to reporters in Keene, said Clinton and her advisers "have no conscience" after a Clinton aide suggested Edwards was using medical victims "as talking points" in his presidential bid. Edwards campaigned with Sarkisyan family members Sunday.

In Saturday's televised debate from Manchester, Clinton acknowledged that Edwards helped the Senate pass a "patient bill of rights," but she noted that the measure died in the House.

"One of the reasons that Nataline may well have died is because there isn't a patient's bill of rights," Clinton said in the debate.