Coming close to tears, Democratic candidate Sen. Hilary Clinton told a small group of voters in a New Hampshire cafe on Monday that her quest for the White House is "very personal."

"It's not easy, it's not easy," Clinton said of the nomination race. "I couldn't do it if I did not passionately believe it was the right thing to do. It's very personal to me."

On the eve of the New Hampshire primaries, polls suggest Clinton trails Sen. Barack Obama.

Clinton -- the national Democratic frontrunner for much of 2007 -- found herself in third place after Iowa on Thursday, with Obama finishing first and former North Carolina senator and 2004 vice-presidential candidate John Edwards finishing second.

"Whatever happens tomorrow, we're going on," said Clinton.

A second loss for Clinton could seriously hurt her chances of eventually winning the Democratic party's nomination.

In New Hampshire, a three-way battle is shaping up between Obama, Clinton and Edwards, who conducted an all-night bus tour that will continue throughout today.

"While everyone else goes to bed tonight, I'm going to be out working," Edwards told an audience in Nashua on Sunday night.

In a USA Today/Gallup poll, Obama had 41 per cent support, compared to 28 per cent for Clinton and 19 per cent for Edwards. No other remaining candidate was in double digits.

At an Obama event at the Lebanon, N.H. Opera House, hundreds couldn't get in to hear the candidate speak. "You guys caught us a little by surprise," Obama told them. "You're the wave and I'm riding it."

During her appearances on morning talk shows, Clinton kept hammering away at Obama's lack of experience.

Obama "is a very talented politician", she said, but "if he's going to be competing for president -- and especially to get the Democratic nomination and go up against whomever the Republicans put up -- I think it is really time to start comparing and contrasting him as I have been scrutinized for all of this year."

Asked on CBS's The Early Show if the Iowa result showed voter disenchantment with her, Clinton said: "I'm just going to work as hard as I can today and tomorrow. ... I feel really good about this whole process, and you know, whatever happens tomorrow, we're going on."

Hillary's husband Bill lost in Iowa in 1992 before finishing a close second in New Hampshire -- even though Gennifer Flowers said she'd had a long-term extramarital affair with him. After his strong finish in New Hampshire, Bill began billing himself as "the Comeback Kid." He went on to win the Democratic nomination and served two terms as U.S. president.

Romney, McCain neck-and-neck

On the Republican side, former frontrunner Republican Mitt Romney hit the streets Monday to drum up needed support.

"We need some voters," he declared.

Romney finished second last week to Mike Huckabee, the former Arkansas governor who struck a populist chord at the Iowa caucuses last week.

Romney's main opponent in New Hampshire is Sen. John McCain of Arizona, who polls suggest is surging.

"Tomorrow is the day when we will tell the world that New Hampshire again has chosen the next president of the United States," McCain told hundreds of supporters.

In the USA Today/Gallup poll, McCain had 34 per cent while Romney had 30 per cent. Huckabee had 13 per cent support. The margin of error is 4.4 percentage points, putting McCain and Romney in a statistical tie.

Some other Republican big names like Rudolph Giuliani and Fred Thompson aren't really campaigning in New Hampshire and have looked ahead to primaries in larger states like South Carolina.

Despite his Iowa win, Huckabee dampened expectations.

"If we come in anywhere in the third and fourth slot, we're going to do great. I'd like to do better than that, but you have people who have had a lot more money spent here," he told CNN.

Some analysts suggest Romney will be cheering for Obama on Tuesday.

New Hampshire's "undeclareds" are the largest group of registered voters in the New England state, and they can vote in either primary. McCain won the New Hampshire primary in 2000 with the support of those independent voters.

Can Obama win it all?

Obama is the first black candidate to seriously challenge for a presidential nomination.

"He has a lot of money. He obviously has momentum at the moment. He's being seen increasingly as electable," Globe and Mail columnist Jeffrey Simpson told CTV's Question Period on Sunday.

"I have a friend who knows Democratic party politics extremely well who still says a black man still can't win in the South. And unless the Democrats can win a couple of southern states, they can't win the White House. We'll have more of an answer to that question in a few weeks time."

In addition, many African-Americans don't see Obama as necessarily being one of them because he's half-white and not a descendant of slaves, Simpson said.

While Clinton targets Obama's lack of experience, Simpson said Obama opposed the Iraq War from the start. Clinton voted to support the war.

Although Clinton has led in national polls, that could evaporate if more people start to see Obama as "the one," Simpson said.

On the Republican side, Simpson said the person with the most to lose in New Hampshire is Romney, who spent $7 million in Iowa only to finish second.

"Most of the population of New Hampshire is in the south. They're very influenced by the Massachusetts media. (Romney is) a former governor of Massachusetts. He'd be well-known in New Hampshire. If he can't win there I think he's finished," Simpson said.

As to who might eventually emerge as the Republican nominee, Simpson said if Romney does lose, the race will be wide open.

Giuliani has money and based his strategy on no clear frontrunner emerging out of Iowa and New Hampshire.

"Huckabee doesn't have the money, but if the evangelicals in other states get behind him, particularly in the South, he'll have the troops that he requires. McCain is considered by a lot of rank and file Republicans to be just a little too wonky," Simpson said.

With files from The Associated Press