Democrats face a week of intense campaigning ahead of Super Tuesday as Barack Obama seeks to parlay his thumping win in South Carolina into a more comprehensive victory over Hillary Clinton when 22 states vote next week.
The scale of Mr Obama's triumph, winning more than twice as many votes as Mrs Clinton, has restored to his campaign the momentum it lost after defeats in New Hampshire and Nevada.
At the end of a campaign marked by bitter exchanges between the two camps, with Mr Obama's supporters accusing Mrs Clinton's of exploiting racial divisions, the Illinois senator told supporters in the state capital of Columbia that South Carolina had embraced a new kind of politics.
"The choice in this election is not between regions or religions or genders. It's not about rich versus poor, young versus old, and it is not about black versus white," he said to loud cheers.
"This election is about the past versus the future. It's about whether we settle for the same divisions and distractions and drama that passes for politics today or whether we reach for a politics of common sense and innovation, a politics of shared sacrifice and shared prosperity."
Four out of five African-American voters chose Mr Obama but he also won a quarter of the white vote, the rest of which Mrs Clinton shared with John Edwards, who came third. Mr Obama won in almost every county in the state and in almost every age group, allowing him to claim that his message of change is resonating throughout American society.
Mr Obama won in South Carolina despite the efforts of former president Bill Clinton, who was campaigning in the state last week. Mr Clinton, who rejected charges that he sought to marginalise Mr Obama as the "black candidate", suggested on Saturday that the outcome was an expression of racial loyalty by African-Americans.
"Jesse Jackson won South Carolina in '84 and '88," Mr Clinton said in answer to a question that did not mention the civil rights campaigner and former presidential candidate. "Jackson ran a good campaign. And Obama ran a good campaign here."
Mrs Clinton left South Carolina before the results were announced on Saturday evening and made only a passing reference to her defeat at a rally in Nashville. She focused instead on Super Tuesday and on tomorrow's primary in Florida.
Mr Obama claimed last week that the Clintons were distorting his record and in his victory speech in Columbia, he sought to make honesty a central issue. "We're up against the idea that it's acceptable to say anything and do anything to win an election. But we know that this is exactly what's wrong with our politics," he said.
Mr Obama won the endorsement of Caroline Kennedy, daughter of president John F Kennedy, who wrote in the New York Times that he embodied her father's vision. "I have never had a president who inspired me the way people tell me that my father inspired them. But for the first time, I believe I have found the man who could be that president - not just for me, but for a new generation of Americans," she wrote.
