Race key to South Carolina vote

Columbia, South Carolina: Democrats voted in South Carolina on Saturday in an unusual contest pitting Barack Obama against two Clintons. Race has been a persistent subtext in the first primary to feature a large number of black voters.

The southern state has become a "must win" state for Obama, whose victory in the Iowa caucuses on January 3 began to fade after he lost contests in Nevada and New Hampshire to Hillary Rodham Clinton. A victory could help reinforce Obama's co-frontrunner status with Clinton, while a loss would severely imperil his candidacy.

Polls showed Obama favoured to win the state in large part due to his strong support among black voters, who are expected to comprise more than 50 per cent of the electorate. The Illinois senator is running to be the first black president.

Obama has made a direct appeal to blacks here after rarely mentioning race throughout the campaign. He will continue that strategy going forward, making trips to Georgia and Alabama later this weekend.

Significant

Both states hold primaries on the multistate "Mega Tuesday" contest on February 5 and feature a significant number of black voters.

Clinton was already looking ahead to February 5, on which 22 of the 50 states hold primary contests, even as the South Carolina primary loomed.

The New York senator, who aims to become America's first woman president, campaigned in California, Arizona and New Jersey early in the week before returning to South Carolina on Thursday. She was headed to Tennessee after the polls close here.

With his wife's attention directed elsewhere, former president Bill Clinton stepped into a starring role in South Carolina - aggressively challenging Obama's record.