Washington.– Barack Obama routed Hillary Rodham Clinton in the racially charged South Carolina primary Saturday night, regaining campaign momentum in the prelude to a Feb. 5 coast-to-coast competition for more than 1,600 Democratic National Convention delegates.

"The choice in this election is not about regions or religions or genders," Obama said at a boisterous victory rally. "It's not about rich versus poor, young versus old and it's not about black versus white. It's about the past versus the future."

The audience chanted "Race doesn't matter" as it awaited Obama to make his appearance after rolling up 55 percent of the vote in a three-way race.

But it did, in a primary that shattered turnout records.

About half the voters were black, according to polling place interviews, and four out of five of them supported Obama. Black women turned out in particularly large numbers. Obama, the first-term Illinois senator, got about a quarter of the white vote while Clinton and former Sen. John Edwards of North Carolina split the rest.

Clinton flew to Nashville as the polls closed, and looked ahead. "Now the eyes of the country turn to Tennessee and the other states voting on Feb. 5," she said, adding "millions and millions of Americans are going to have their voices heard."

Edwards finished a distant third, a sharp setback in the state where he was born and scored a primary victory in his first presidential campaign four years ago. Even so, he vowed to remain in the race, his goal, he said, to "give voice to all those whose voices aren't being heard."

The victory was Obama's first since he won the kickoff Iowa caucuses on Jan. 3. Clinton, a New York senator and former first lady, scored an upset in the New Hampshire primary a few days later. They split the Nevada caucuses, she winning the turnout race, he gaining a one-delegate margin. In an historic race, she hopes to become the first woman to occupy the White House, and Obama is the strongest black contender in history.

The South Carolina primary marked the end of the first phase of the campaign for the Democratic nomination, a series of single-state contests that winnowed the field, conferred co-front-runner status on Clinton and Obama but had relatively few delegates at stake.