In the most intense and personal exchange of the presidential campaign, Senators Hillary Rodham Clinton and Barack Obama assailed each other’s integrity and voting records during a televised debate on Monday in South Carolina, the site of a critical primary in five days.If the debate was full of memorable moments — Clinton accusing Obama of associating with a “slum landlord”, Obama saying he felt as if he were running against both Hillary and Bill Clinton, the two candidates talking over each other— the totality of the attacks also laid bare the ill will and competitive ferocity that has been simmering between them for weeks.“You know, Senator Obama, it is very difficult having a straight-up debate with you, because you never take responsibility for any vote, and that has been a pattern.” Clinton said at the Palace Theater in Myrtle Beach.Obama shot back that Clinton was conducting a brand of negative politics that, he suggested throughout the night, she and her husband had perfected: “comb my 4,000 votes in Illinois, choose one, try to present it in the worst possible light”. As she has never done before, Clinton linked Obama to a longtime fundraiser, whom she characterised as a slumlord in “inner-city Chicago”. Clinton was referring to Obama’s ties to Antoin Rezko, a Chicago businessman who was indicted last fall on federal charges of business fraud and influence peddling connected to the administration of Governor Rod R Blagojevich of Illinois. Obama did work for a law firm in Chicago and performed legal work involving Rezko’s housing developments. On Saturday, Obama returned more than $40,000 in political contributions that were linked to Rezko. And Obama, who appeared on the verge of losing his temper at times, noted that she was on the board of Wal-Mart while he was working on “the streets” as a Chicago community organiser. Clinton was a director of Wal-Mart from 1986 to 1992.The third Democratic contender, John Edwards had to fight to speak. He tried to portray himself as the only candidate who was focusing on the real issues, criticising the others for squabbling among themselves when health care and other issues go unresolved. At the same time, he tried make an appeal for his own electability in November against a Republican candidate like John McCain, saying he could “go every place” in the country to campaign. Obama was as heated and intense as he has been at any debate over the last year. At times, he appeared angry and close to expressing it at Clinton and also at her husband, Bill Clinton, whom Obama criticised frequently during the debate for what he said were distortions of his views and record by the former president.“I’m here,” Clinton said, “not my husband”.Obama snapped, “I can’t tell who I’m running against sometimes.” At several other points, he used the phrase “Senator Clinton and President Clinton” to re-enforce his view that he is facing off against a decades-old Clinton machine.Obama, who would be the nation’s first black president, was asked about how the author Toni Morrison had bestowed that title on Clinton more than a decade ago.“I think Bill Clinton did have an enormous affinity with the African-American community,” Obama said, praising Clinton for his longtime commitment to racial equality as a man who grew up in the South. Lightening the moment, he added: “I would have to investigate more Bill’s dancing abilities and some of this other stuff before I accurately judged whether in fact he was a brother.” Clinton replied, “I am sure that can be arranged.” South Carolina, Florida Republican raceRepublican presidential candidates are trying new tactics in the run-up to Florida's GOP primary. Polls show a tight four-way race between McCain, Romney, Huckabee and Giuliani. .Democratic raceFive days before the Democratic primary in South Carolina, Obama leads in polls, having overtaken Clinton's early substantial lead. Black voters are expected to cast half or more of the ballots in Saturday's primary.