MANCHESTER, N.H. — Amid a widespread sense in the Granite State that Senator Clinton’s chances of becoming the first woman president in American history are sinking, Mrs. Clinton will fight her way through the rest of the campaign vowing “to examine everyone’s record.”

Without appearing face-to-face yesterday with her main rival here, Senator Obama, she responded to him. She had criticized his campaign for raising “false hopes.” Mr. Obama then asked what would have happened if President Kennedy had not called for a man on the moon or Martin Luther King Jr. had not led the March on Washington. Her retort amounted to a 2008 version of Senator Bentsen’s jab at Senator Quayle, “You’re no Jack Kennedy.”

“He used John F. Kennedy and Martin Luther King to criticize me,” she said, noting that “President Kennedy was in the Congress for 14 years” and was a “war hero” and that King was “gassed,” “beaten,” and “jailed.” She added, “I’m not asking you to take me on a leap of faith.”

Mrs. Clinton said she is the best potential nominee for the Democratic Party in November because she is battle-tested, a theme likely to be heard in coming weeks if she is defeated here in today’s first-in-the-nation primary. With the latest CNN/WMUR poll showing Mr. Obama leading Mrs. Clinton by 39% to 30%, her campaign is struggling with how to turn back what Mr. Obama calls a “wave” he is riding.

During an appearance in Salem, N.H., Mrs. Clinton and her supporters attempted to make the case that she is the best potential Democratic candidate because she and her husband have been thoroughly vetted. “It is important to nominate a Democrat who can go the distance against the Republicans,” she said. “We can’t expect any kid gloves treatment from the Republicans.”

Mrs. Clinton was introduced in Salem by Susan Lynch, who is the wife of New Hampshire’s governor, John Lynch. Mrs. Lynch said that Mrs. Clinton “has stood up to the criticism and she’s still here.”

Both comments reflected what will likely be a theme of Mrs. Clinton’s campaign as it attempts to survive beyond the four weeks that will pass between the New Hampshire primary and the series of contests on February 5, including three more debates. The campaign hopes that time will serve as a cooling off period that can take some luster off of Mr. Obama.

Mrs. Clinton and her backers will emphasize the 16 years of rigorous questioning and tough stories she has received from journalists, and argue that Mr. Obama has so far largely escaped scrutiny.

The expectation of the Clinton forces is that her strong field organization can prevent a New Hampshire loss from turning into an unmitigated disaster. If, as polls suggest, John Edwards falls to a distant third, Mrs. Clinton can then portray the race as being between two people, herself and Mr. Obama. “We need to ask first and most importantly, who will be the best president and who will be the Democrat who can take us to victory,” she said last night.

It will be a tough road. Mrs. Clinton seems to be facing a campaign that is more than a routine political organization.

The intensified interest in Mr. Obama’s campaign sparked an impromptu scene in Lebanon, N.H., when he stopped to stand atop stone steps and address 400 voters who were shut out from his scheduled speech when the overflow crowd exceeded the space available.

“You guys caught us a little bit by surprise,” Mr. Obama said, holding a hand-held microphone. “What we’re seeing here today, all of you, is representative of what is happening all across the country. The people of Iowa last week stood up for change. And in one day’s time you have a chance to do the same thing.”

But Mrs. Clinton may find maintaining momentum in the face of two consecutive and unexpected victories by Mr. Obama difficult to deal with.

“They’re in a difficult position,” Mr. Obama’s chief campaign adviser, David Axelrod, told The New York Sun from the lobby of Lebanon City Hall, near where Mr. Obama was making his speech. He said he thought it would be hard for the Clinton to come up with a strategy to counteract what he called a “galvanization” especially on “tactical” grounds.” “This is a tough thing to spin,” he said.

Asked whether he had ever seen a candidate who could animate crowds as Mr. Obama had just outside City Hall, Mr. Axelrod said “no.”

Mr. Axelrod called Mrs. Clinton “formidable” and said he expected a tough fight throughout the rest of the campaign. “We’ve been organizing assiduously in South Carolina and Nevada,” Mr. Axelrod said. “If you win a series of contests it gives you a considerable amount of forward momentum.”

Mrs. Clinton is vowing to stay in the campaign for the long haul despite a rare display of vulnerability on the campaign trail.

Speaking to undecided voters in Portsmouth, her eyes welled up with tears when asked how she kept going in the arduous campaign. “This is very personal for me. It’s not just political. It’s not just public,” she said, according to the Associated Press.

She will also keep trying to remind voters that she is a woman. During her speech in Salem, two hecklers rose to chant and hold signs, saying “Iron My Shirt.”

After asking that the lights in the hall be turned brighter, she said, “Oh, the remnants of sexism alive and well” as police removed the hecklers. “As has just been demonstrated, I am also running to break through the highest and hardest glass ceiling,” she added, to enthusiastic applause.

Speaking at a raucus rally for more than 4,000 supporters, the foundation of her field operation here, Mrs. Clinton evoked President Clinton’s 1992 language prior to the New Hampshire primary after which he emerged “the Comeback Kid.” Her voice loud and somewhat hoarse, she shouted, “If New Hampshire will be there for me tomorrow, I will always be there for you,” one of Mr. Clinton’s signature lines during his bid for the presidency. While her overall tone was positive, she said at one point, with Mr. Clinton at her side, “We’ll all be fine no matter what happens.”