Democrat Barack Obama won most of the votes from women, blacks and Hispanics and siphoned off enough white support to leave Republican John McCain with no way to win.
Exit polls showed that McCain won the votes of 55 per cent of white voters, whose strong support has been vital to the success of winning Republican presidential candidates. But he did not get a wide enough margin to compensate for the lopsided support that Obama drew from other voters who make up a quarter of the electorate.
McCain and Obama split whites across the US except in the South, where McCain got twice as many white votes as Obama. Southern whites had favored Republican George Bush by similar margins in his 2000 and 2004 wins.
Obama, who will become the first black president and at age 47 one of the youngest, ran away with the youth vote. He won the under-30 crowd by 34 per centage points, even better than Democrat Bill Clinton's 19-point advantage when he defeated Bob Dole in 1996. He was the choice of nearly seven in 10 first-time voters of all ages.
Forty per cent of those voting called themselves Democrats — a historically high number — and they overwhelmingly chose Obama. He also held a significant edge among the quarter of voters who called themselves independents.
McCain, 72, was the choice of just over half of senior citizens, coveted for their vigilance in going to the polls. Those 65 years and older were 16 per cent of all voters, similar in influence to people under 30.
McCain drew some of his strongest support from white, working-class voters, winning 58 per cent of their vote. But it was shy of the 23-point margin by which Bush won the votes of whites without a college degree in 2004.
Enthusiasm clearly was on Obama's side: Almost six in 10 of his voters said they were excited about what Obama would do as president. Fewer than three in 10 McCain voters felt that way about their man, according to the exit polls.
Curt Babura, a 31-year-old cook from Cleveland, said he never bothered to vote before casting his ballot for Obama. "When he talks it feels like he's talking to you," Babura said.
Fear played no favorites. Among both Obama and McCain voters, about half said they were scared of what the candidate they opposed would do as president.
"I'm scared to death of the Democratic Party this year, particularly Barack Obama," said Robert Zannini, a 73-year-old retired Air Force pilot from Montgomery, Alabama. "Everything he says seems to lead to socialism."
Obama drew the votes of two-thirds of Hispanic voters — heavily courted by both candidates — and 95 per cent of blacks who went to the polls.
He seemed to inspire optimism about race in America. About 60 per cent of Obama's voters believe race relations will improve over the next few years, and only 7 per cent predict they will deteriorate. In contrast, almost two-thirds of McCain's voters expected racial tensions to stay the same or worsen.
In both camps, one voter out of five acknowledged that the candidates' race was a factor in their vote, but almost no one said it was the most important factor.
A healthy lead among women voters typically is key to a Democratic presidential victory, and Obama attracted 56 per cent of their votes. He split the overall male vote with McCain.
Obama cleaned up with his effort to mobilize potential supporters who had never voted before. Among first-time voters, one in five was black, almost twice the proportion of blacks among voters overall. Another one in five was Hispanic. Two-thirds of new voters were under 30. Almost half were Democrats, and a third called themselves independents.
Twenty-six-year-old Jennifer Sunderlin, who typically votes Republican, said she did not stick with her usual party this election.
"Don't tell my Dad, but I voted for Barack Obama," said Sunderlin, of Albany, New York. She said she was turned off by McCain's choice of Alaska Gov. Sarah Palin as his running mate.
She was not alone. Four in 10 voters overall said Palin was an important factor in deciding whom to vote for, and this group was about as likely to vote for Obama as McCain. But nine in 10 Republicans calling Palin's selection important were voting for McCain.
A third of voters said the quality that mattered most to them was the candidates' ability to bring change — the mantra of Obama's campaign. But almost as many cited the candidates' values, and they mostly voted McCain, as did the vast majority of those who honed in on experience.
"I don't think Obama knows what he's doing," said Craig Burnett, 55, a Republican in Hagerstown, Maryland. "He's too young and inexperienced."
Two-thirds of voters worried about how to pay for their health care and even more feared terrorists will attack the US again. But the nation's troubled economy weighed heaviest on their minds.
Six in 10 voters picked the economy as the most important issue facing the nation. None of the four other issues listed by exit pollsters — energy, war in Iraq, terrorism and health care — was chosen by more than one in 10 people.
Almost everyone agreed the economy is in either a "poor" or "not good" condition.
The results were from exit polling by Edison Media Research and Mitofsky International for The Associated Press and television networks conducted in 300 precincts nationally. The preliminary data was based on 17,834 voters, including telephone polling of 2,407 people who voted early, and has a margin of sampling error of plus or minus 1 per centage point for the entire sample, smaller for subgroups.Reuse content