Illinois Sen. Barack Obama trounced his New York counterpart, Sen. Hillary Clinton, in Saturday's South Carolina primary, giving his campaign a significant boost as the race for the Democratic presidential nomination heads into a crucial phase.With 99% of precincts reporting, Obama had 55% of the vote, Clinton had 27% and former North Carolina Sen. John Edwards had 18%, according to The New York Times. Obama is hoping to become the first black U.S. president, and the South Carolina primary was closely watched as a test of how African Americans in other states may cast their votes. According to the AP, which cited polling place interviews, about half of the South Carolina voters were black, and four out of five of them supported Obama. The AP also reported that black women turned out in large numbers. Obama, who throughout his campaign has presented himself as a unifier and consensus builder, downplayed racial and other divisions in a speech at a campaign rally. "The choice in this election is not about regions or religions or genders," Obama was quoted saying by the AP. "It's not about rich vs. poor, young vs. old and it's not about black vs. white. It's about the past vs. the future." After the polls closed, former first lady Clinton flew to Tennessee for a campaign rally. The The New York Times reported that she conceded the South Carolina primary in a brief statement: "We now turn our attention to the millions of Americans who will make their voices heard in Florida and the 22 states, as well as American Samoa, who will vote on Feb. 5." Florida will hold its primary on Tuesday. A week later, on Feb. 5, 22 states will hold contests, including New York and California, which both have large numbers of delegates. The South Carolina results were a blow to Edwards, who was born in the state and had campaigned as a native son.