Democrat Barack Obama appeared poised to defeat Hillary Clinton for the second time in less than a week tonight as voters streamed into polling stations in New Hampshire in the US first presidential primary election.
On the Republican side, John McCain and Mitt Romney competed head-to-head in a race that could sink the presidential aspirations of one of them. Polls indicated Mr McCain had an edge but no clear-cut advantage.
Democratic candidate Hillary Rodham-Clinton hands out coffee outside a Dunkin Donuts in New Hampshire
Mr Obama declared Americans were ready to "cast aside cynicism" as he looked for a convincing win in the Democratic contest.
Wins in such early contests as the New Hampshire primary and last week's caucuses in Iowa are crucial in building momentum as candidates compete state-by-state for delegates to this summer's party conventions, where one candidate from each party will be named to move on towards the November national election to succeed George W. Bush.
Ms Clinton, who is hoping to become America's first female president, has been running second in the New Hampshire surveys, with former Senator John Edwards third. The former first lady and her aides seemed to be bracing for another setback following Mr Obama's win in Iowa last week.
"Today you can make your voice heard — you can insist that change will come," Mr Obama told a crowd at Dartmouth College. "The American people have decided for the first time in a very long time to cast aside cynicism, to cast aside fear, to cast aside doubts."
Looking back at his Iowa victory, the man who would be the first black president said: "The state was not, according to the experts, designed for me. There were not a lot of people who look like me in Iowa."
Polls indicated Mr Obama, whose father is Kenyan, had pulled ahead of Mrs Clinton.
Former President Bill Clinton, dampened expectations for his wife, saying the unusually short stretch between Iowa and New Hampshire presented little chance to counter Mr Obama's momentum.
"It takes some time to undo that; for people to say, 'Well, this is our race in our state and we're going to think about this and give all these candidates a free shot'," he said. "If this were 10 days after Iowa, instead of five, I believe we would have no doubt about what the outcome would be."
Ms Clinton was hard at work this morning, as she and her daughter Chelsea poured coffee for voters and a police officer at a Manchester primary school before dawn, greeted by a dozen voters and twice as many supporters outside. "We're going to work all day to get the vote out," she said.
Her next stop was at a polling place in a Nashua high school, where pupils who had just arrived by bus screamed with excitement and enveloped her.
The gym at Dartmouth where Mr Obama was speaking was only about two-thirds full, in contrast with his packed events over the last few days. A young woman near the front of the crowd fainted and he stopped his speech for nine minutes, staring down with his arms crossed, until she was taken out on a stretcher, alert and talking.
TNS Media Intelligence.cmag, a firm that tracks political advertising, said Ms Clinton spent $5.4 million dollars to reach New Hampshire voters, and Mr Obama spent $5 million. The total for Edwards was $1.7 million, reflecting a smaller campaign treasury. New Mexico Governor Bill Richardson, the fourth candidate in the race, could afford about $500,000 dollars.
As was the case in Iowa, Mr Romney spent more than his rivals combined on television for the New Hampshire primary.