AP VoteCast: Black voters carry Biden to his first victory

Vice President Joe Biden has for weeks looked to the black voters of South Carolina to hand a win to his flagging campaign.Biden won 61% of the votes cast by non-white voters, dominating a crowded Democratic field among a group that made up more than half of the electorate.Biden also performed strongly with older voters, women, regular churchgoers and moderates and conservatives, according to AP VoteCast, a wide-ranging survey of more than 1,400 voters in South Carolina's Democratic primary.