McCain wasn't nearly as reluctant. "We're not gonna lose here," he boasted as he set out on a packed day of campaigning through seven cities. In a snow-draped setting in Keene, there seemed little doubt he had Romney in mind when he said voters would reject negative campaigning. "I don't care how many attack ads you buy on television," he said.

Romney has run several TV commercials against McCain in New Hampshire, arguing that the senator's immigration plan would offer amnesty for illegal immigrants and painting him as a disloyal Republican for twice opposing President Bush's tax cuts. McCain responded with an ad that includes a quote from The Concord Monitor that suggested Romney was a phony.

Obama won his Iowa victory on a promise of bringing change to Washington, trumping Clinton's stress on experience. She has struggled to find her footing in the days since, at the same time insisting she is in the race to stay.

Her husband, the former president, pointed out the obvious Sunday night in remarks before a college audience. "We can't be a new story," he said, speaking in something of a jocular tone. "I can't make her younger, taller, male."

Still, Sen. Clinton's aides have urged her to show more passion and emotion — including laughter — to give voters a sense of her warmer side.

By coincidence or not, she did so as she set out on a final day in New Hampshire.

"You know, I had so many opportunities from this country. I just don't want to see us fall backwards," she said at a morning campaign stop, her tone changing and voice quavering.

"You know, this is very personal for me. It's not just political. It's not just public. I see what's happening. And we have to reverse it."

Edwards criticized Clinton as ill-suited to bring about change. "The candidate — Democrat or Republican — who's taken the most money from drug companies is not a Republican. It's a Democrat, and she's in this race tomorrow morning," he said.

The ubiquitous polls suggested that independents would play a large role in determining the outcome of the Republican race.

Political independents accounted for 41 percent of the vote in the 2000 Republican primary in the state. McCain carried that group, 61-19, over George W. Bush and won the primary. Bush won the GOP nomination.

Now, eight years later, McCain again hopes to attract enough independent voters to defeat Romney.

But Obama's rise presents a challenge McCain didn't face in 2000. The Illinois senator showed strong appeal among independents in Iowa, and pre-primary polling in New Hampshire indicates he is poised to gain substantial backing there as well.