The electoral victory of Barack Obama in South Carolina has revealed a Democratic electorate divided by race, gender and age.
By Steve Schifferes
Race, age and gender were all factors at play in South Carolina
Mr Obama swept the black vote, which makes up more than half of those voting in this Democratic primary, although only 28% of the state's population.
Hillary Clinton maintained her strengths, especially among women and older voters, that have been evident in previous primary elections.
And former Senator John Edwards, running as a southerner from South Carolina, had a relatively strong showing, and did particularly well among white men.
Mr Obama's victory was based on his overwhelming support among the black community, which voted 78% in his favour, while 24% of white Democrats backed his presidential bid.
In South Carolina, African-Americans made up 53% of Democratic primary voters.
In contrast, Senator Clinton and John Edwards split the white vote, with each gaining just under 40%.
Mrs Clinton's slender margin of victory over Mr Edwards was provided by the 19% of blacks who voted for her. Only 3% of the black vote went to Mr Edwards.
Among black voters, Mrs Clinton had more appeal to older voters and women, but the effect was not as marked as among white voters.
And in another measure of racial polarisation, the quarter of voters who said they thought the country was not ready for a black president gave Mrs Clinton a majority of votes, while 77% of those who believed the country was definitely ready for a black president voted for Mr Obama.
There was clear evidence of a generational divide, with Mr Obama winning 70% of the votes of those between 25 and 29, but only 51% of those between 50 and 65.
Mrs Clinton, in fact, won more votes - 40% - among retired people over 65 than Mr Obama.
And among older white voters, over 60, Mr Obama only received 15% of the vote.
In contrast, Mr Obama ran most strongly among new voters who had never voted before.
Among white voters, women and men voted quite differently.
John Edwards had a lead among male voters, by 45% to 28% for Mrs Clinton, with 27% of white men voting for Mr Obama.
However, among white women, Hillary Clinton was ahead, with 42% of their votes, compared to 36% for Mr Edwards and 22% for Mr Obama.
Mrs Clinton also did equally well among married women and unmarried women. In the past, she has sometimes received more voters from single women.
As in past primaries, Mr Obama appealed more strongly to those who were concerned about the Iraq war than those who were most worried about the economy, but the effect was less marked than in previous contests.
More than half of Democratic voters thought the economy was the most important issue, while only 19% cited the Iraq war, third behind health care.
And among black voters, who are much poorer than whites in South Carolina, the economy was clearly the most important issue.
However, Mrs Clinton got a higher percentage of the vote among those who thought national economic conditions were poor than among those who thought that they were good.
Mr Obama got the strongest support among voters who wanted an immediate troop withdrawal from Iraq, while Mr Edwards won strongest support among those who wanted the troops to stay, suggesting that he was also benefiting from a cross-over vote among Republicans who were also eligible to vote in this primary.
Perceptions about the candidates' relative strengths and weaknesses played a bigger role in the election.
Mr Obama was overwhelmingly judged the candidate who could most bring about change, and three out of four voters who thought that was the most important quality in a candidate voted for him.
Mrs Clinton was equally the strong choice of those who believed that experience was the most important quality for a candidate.
Mr Edwards, who has been running on a populist platform, gained the most support among those who wanted a candidate who cares about ordinary people.
But interestingly, among those who said that electability was most important, opinion split more evenly between Mr Obama (40%) and Mrs Clinton (36%).
The analysis is based on exit polls conducted during the election, with a sample size of 1,905.
Looking to the future
In 10 days, nearly half of the US electorate will have a chance to vote on their choice of presidential candidates in momre than 20 states in Super Tuesday on 5 February.
Mr Obama's strong showing in South Carolina certainly gives him momentum, but he will have to appeal to white as well as black voters to win the big states such as New York, California and Illinois.
And to win in November, he will also have to reach out to moderates and independents in the electorate - who only gave him 46% of the vote in South Carolina.
Mr Obama also has to overcome what appears to be a reluctance of older white voters to support a black candidate.
Mrs Clinton faces a different task. She needs to re-energise her white working-class base, which was squeezed from both sides in South Carolina by Mr Edwards and Mr Obama.
And she needs to broaden her appeal to voters who go to church regularly. Mrs Clinton ran much more strongly among non-church goers, while Mr Obama got the voters of two-thirds of the most frequent attendees.
The battlegrounds in the Democratic primary race are becoming clear. It will now be up to the opposing camps to see how well they can mobilise their natural supporters in order to win the day.