The Democratic presidential race moves to South Carolina as Republicans look to Florida following Hillary Clinton's defeat of Barack Obama in Nevada's caucus and John McCain's victory in South Carolina's Republican primary.
The Nevada result has increased pressure on Mr Obama to win in South Carolina, where African-American voters could be decisive and may constitute half the Democratic electorate in next Saturday's primary.
Mr Obama won more than 80 per cent of the black vote in Nevada but he lost heavily to Mrs Clinton among women and Hispanic voters. The Clinton campaign has made clear that it will fight for every African-American vote in South Carolina, with former president Bill Clinton promising to campaign door to door in black neighbourhoods. "Eleven days ago people were dancing on Hillary's grave - we have another thing coming now," Mr Clinton said.
Mr McCain's narrow victory in South Carolina over former Arkansas governor Mike Huckabee has given his campaign momentum within a Republican field that remains wide open, with four candidates still capable of winning the nomination. Winning in the state that doomed his 2000 presidential run was especially sweet for Mr McCain, who joked about his comeback in a speech to jubilant supporters in Charleston. "It took us a while, but what's eight years among friends?" he said.
Mr McCain owed his victory in part to the support of independent voters, who will not be allowed to take part in Florida's primary on January 29th. He has a slight lead in Florida but will face a tough, four-way battle with Mr Huckabee, former Massachusetts governor Mitt Romney and former New York mayor Rudy Giuliani.
Mr Giuliani, who has ignored most of the early-voting states and came close to last in all of them, is staking everything on a victory in Florida to propel him into a commanding position on February 5th, when more than 20 states vote.
Mr Romney won Saturday's Republican caucus in Nevada, where he was the only major candidate to campaign seriously. With victories in Michigan and Wyoming, he has won more delegates to the national convention, which will choose the party's nominee, than any other candidate. Mr Huckabee remains strong among evangelical Christians, who are an important constituency in northern Florida and he could benefit from the expected withdrawal from the race of fellow conservative Fred Thompson.
Although Mrs Clinton won 51 per cent of the caucus vote in Nevada compared to Mr Obama's 45 per cent, the Obama campaign claimed that because of the geographical spread of its vote, the Illinois senator will secure more delegates - 13 to Mrs Clinton's 12.
Mr Obama lost the popular vote despite the support of the powerful Culinary Workers' Union, which represents many of those who work at the casinos and hotels in Las Vegas. Indeed, Mrs Clinton won almost all the caucuses held in casinos along the Las Vegas Strip, reflecting her 65 per cent support among Hispanic voters.
Speaking in Atlanta yesterday from the pulpit of Martin Luther King's Ebenezer Baptist Church, Mr Obama returned to his central theme of the need for a new kind of politics to transcend divisions.
"The divisions, the stereotypes, the scapegoating, the ease with which we blame the plight of ourselves on others, all of that distracts us from the common challenges we face: war and poverty; inequality and injustice," he said.
Speaking in Harlem after she received the endorsement of Calvin Butts, a leading black pastor, Mrs Clinton said that a vote for her should not be seen as a vote against Mr Obama. "I have the highest regard and admiration for my friend and colleague Senator Barack Obama. He is an extraordinary person with many gifts and contributions to our country and the world. I am honoured to be running with him," she said.