US:Democrats vote today as new polls show Barack Obama with a clear lead over Hillary Clinton despite a dramatic drop in his support among South Carolina's white voters in recent days. An MSNBC/McClatchy poll gives Mr Obama an eight-point lead with 38 per cent to Mrs Clinton's 30 per cent of likely voters, and 19 per cent for John Edwards.
The poll shows, however, that Mr Obama's support is almost entirely concentrated within the black community and that his support among whites in South Carolina has plunged from 20 per cent to 10 per cent within a single week. Most of the white voters who have turned away from Mr Obama appear to have gone to Mr Edwards, a native of South Carolina who is now the first choice among whites although he is in third place overall.
The campaign in South Carolina has been marked by the sharpest exchanges so far between Mrs Clinton and Mr Obama, and some of Mr Obama's supporters claim that the Clinton campaign is sending out surreptitious signals that highlight racial divisions. They point to a remark by former president Bill Clinton this week to the effect that Mr Obama was benefiting from the loyalty of black voters.
"As far as I can tell, neither Senator Obama nor Hillary have lost votes because of their race or gender. They are getting votes, to be sure, because of their race or gender - that's why people tell me Hillary doesn't have a chance of winning here," Mr Clinton told an audience in Charleston. "But that's understandable because people are proud when someone who they identify with emerges for the first time."
Mr Edwards appears to have been the main beneficiary of the squabbling between the other candidates, as his support has risen sharply this week. As in the earlier contests of the presidential campaign, however, the outcome in South Carolina could turn on the success of each campaign in turning out its voters.
The Democratic field narrowed to three yesterday when Ohio congressman Dennis Kucinich withdrew from the race to focus on a tough battle to retain his congressional seat in November. Mr Kucinich, who voted against the Iraq war and favours a nationalised health system, has won little support from voters but saw other candidates move closer to his positions on key issues in recent months.
Republicans, who voted in South Carolina last Saturday, face their next contest in Florida next Tuesday with polls showing John McCain and Mitt Romney vying for the lead, ahead of Mike Huckabee and Rudy Giuliani.
Mr Romney, a former venture capitalist, hopes that the emergence of the economy as the biggest issue will propel him to victory. "The only way to get America on track economically is to have a president who actually understands how the economy works," he said.
As the only candidate to have won two primaries so far, Mr McCain is betting that a victory in Florida will make him the prohibitive favourite ahead of Super Tuesday on February 5th.
Mr Giuliani has staked everything on winning Florida but he is trailing badly in the polls and received a stinging rebuke yesterday from the New York Times, which announced its endorsement of Mrs Clinton and Mr McCain.
"The real Mr Giuliani, whom many New Yorkers came to know and mistrust, is a narrow, obsessively secretive, vindictive man who saw no need to limit police power," the paper said.
"The Rudolph Giuliani of 2008 first shamelessly turned the horror of 9/11 into a lucrative business, with a secret client list, then exploited his city's and the country's nightmare to promote his presidential campaign."