CONCORD, N.H. — The wounded contenders of Iowa took on the presumed leaders of the pack in the New Hampshire presidential primary campaign today, disparaging Senator McCain as a creature of Washington and signaling that Senator Obama’s mantle as the agent of change is ripe for challenge.

“It will be a different race here,” Mr. Romney vowed, bidding to keep his GOP campaign viable. His immediate difference: switching the focus of his criticism from the Iowa winner, Michael Huckabee, to Mr. McCain, the Arizona senator staging a 2008 revival in the state he won in 2000. Similarly, Senator Clinton made clear she considered Mr. Obama’s positions fair game for attack.

“It’s hard to know exactly where he stands and people need to ask that,” she said. “I think everybody is supposed to be vetted and tested.”

Mr. Obama, the Illinois senator who punctured Mrs. Clinton’s front-runner status in his convincing Iowa win, rallied in Portsmouth and Concord. He playfully but pointedly addressed the Clinton campaign’s earlier criticisms of him as an overambitious figure who wanted to be president ever since he started grade school.

“This feels good,” he told a rally in an airport hangar in Portsmouth. “This feels just like I imagined when I was talking to my kindergarten teacher.” The crowd laughed. Earlier, Mr. Obama said he saw no reason to revamp his campaign for the new realities of New Hampshire: “No, it’s not broken, why fix it?”

Mr. Romney attributed Mr. Huckabee’s Iowa win largely to his background as a Southern Baptist preacher in a state with a decisive bloc of evangelical voters, an element missing in New Hampshire. “It was a wonderful strategy that he pursued effectively,” he said. “I don’t think that’s the strategy that’s going to work in every state.”

In any event, New Hampshire presented a different political alignment, with precious little time for candidates to remake their campaigns and adapt. Messrs. McCain and Romney have been neck and neck here in pre-Iowa surveys, with Mr. Huckabee lagging, while Mrs. Clinton and Mr. Obama have topped polls on the Democratic side.

Mr. Romney said the message coming out of Iowa was a hunger for change and contended he, not the longtime Arizona senator, could make that happen.

“There’s no way Senator McCain can come to New Hampshire and say he can be the candidate to change Washington,” the former Massachusetts governor said. “He is Washington.”

Mr. McCain called Mr. Romney’s attacks against Mr. Huckabee in Iowa “a little bit desperate. It didn’t work in Iowa, I don’t think it will work in New Hampshire.”

Stopping in the eye-care section of the Hollis (N.H.) Pharmacy, surrounded by supporters, Mr. McCain recalled his early pressure on the Bush administration to put more troops in Iraq as one example of a career devoted to changing Washington’s ways.

“I’m most proud of the change I brought about in Iraq that saved American lives,” Mr. McCain said. “No one else was ready to make that kind of reform. I’m proud to stand here as a person who has reformed and reformed and reformed.”

Mrs. Clinton hoped to become her family’s newest “Comeback Kid” in a state that revived President Clinton’s run for the Democratic nomination in 1992.

She promised a rally at the Nashua airport that she would answer as many questions as possible about her candidacy in the short run to the primary, and addressed several about her electability after her Iowa defeat.

“Anyone we nominate will be thrown into that blazing inferno of a general election,” she said. “I’ve been through the fires, and it makes it far less likely they are going to be able to do to me what they intend to do to whomever we nominate.” She was traveling through the state in a lavishly painted campaign bus bearing her latest slogan: “Big Challenges, Real Solutions — Time to Pick a President.”

Fond words about grass-roots politicking with Iowans and their caucus meetings seemed distant, just a day after the event, as she cast the New Hampshire primary Tuesday as a truer expression of democracy.

“This is a primary election,” she said. “You’re not disenfranchised if you work at night. You actually can come out and vote. You’re not disenfranchised if you’re not in the state. You can actually send in an absentee ballot. So this is going to be a much more representative electorate because we’ve got people who are going to be able to express opinions in the way we run elections in America.”

Mr. Huckabee, on the morning talk shows, pitched his tax plan to anti-tax New Hampshire Republicans, and asserted his campaign is about much more than the Christian conservatives who lifted him in Iowa. “What we’re seeing is that this campaign is not just about people who have religious fervor,” he said. “It’s about people who love America, but want it to be better and believe that change is necessary and it’s not going to happen from within Washington.”

Iowa’s results tightened the Democratic field — Senator Biden and Dodd dropped out shortly after the outcome was clear last night. John Edwards mounted an energetic, populist campaign only to see himself repeat his 2004 second place finish in Iowa. He vowed to continue, but he trails Mr. Obama and Mrs. Clinton in polls and in money. Mrs. Clinton sank to third.

Mr. Edwards portrayed the Democratic race as one between Mr. Obama and him.

“People are going to decide between a candidate who is not the candidate of money, not the candidate of the status quo, but somebody who will actually fight for the changes we need, and it will be between Senator Obama and myself,” he said.

On the Republican side, Mr. Huckabee enters New Hampshire with little money and little time to mount an adequate come-from-behind surge. And tradition pulls against him. President George H. W. Bush in 1980, Bob Dole in 1988 and 1996, and President George W. Bush in 2000 — all are Iowa caucus winners who lost their New Hampshire primaries.

Mr. Huckabee’s Iowa victory served to keep the GOP contest wide open. He won by 9 percentage points and Mr. Romney now faces a reinvigorated Mr. McCain. Fred Thompson was looking beyond New Hampshire to South Carolina. And Mayor Giuliani, fading in New Hampshire, was counting on Florida and big state contests on February 5.

In Iowa, Mr. Thompson held on to a third-place finish over by Mr. McCain by fewer than 300 votes, with 96% of GOP precincts reporting. Mr. McCain spent little time or money there, investing his early hopes in New Hampshire.

An unpredictable factor in New Hampshire could be Rep. Ron Paul, an anti-war congressman with libertarian views whose legions of volunteers have fanned out across New Hampshire waving placards and knocking on doors in support of their dark horse candidate. Mr. Paul has raised a surprising amount of money, further complicating the political calculations in the state.