Hillary Clinton and Barack Obama, two of the Democratic Party candidates for the US presidency, have clashed in a debate before South Carolina's primary.
The two frontrunners spoke out strongly against each other
Mr Obama accused Mrs Clinton of saying anything to get elected. On Sunday he had accused her husband Bill Clinton of making false statements about him.
But Mrs Clinton said it was hard to debate with someone who never took responsibility for any vote he cast.
A third candidate, John Edwards, accused them of squabbling.
The three candidates also debated the economy and racial justice, with attacks on President George W Bush's plan to stave off recession.
Mr Obama needs to win Saturday's South Carolina primary to re-invigorate his campaign after successive defeats to the former first lady in New Hampshire and Nevada.
The debate marked a significant gear-shift with just two weeks before "Super Tuesday", when 22 states vote in a potentially decisive day for the party's nomination contest.
Monday's often acrimonious debate saw heated exchanges in which the Illinois senator told Mrs Clinton that he was helping unemployed workers on the streets of Chicago when "you were a corporate lawyer sitting on the board at Wal-Mart".
The New York senator retorted that she was fighting against misguided Republican policies "when you were practising law and representing your contributor ... in his slum landlord business in inner city Chicago", a reference to Antoin Tony Rezko, who is facing charges for fraud.
Mr Obama's campaign has given to charity the funds which it has received from donors linked to Mr Rezko.
With Monday marking a national holiday to honour the slain civil rights leader Martin Luther King, and more than half of South Carolina's voters being black, racial equality was also addressed.
Trailing the two front-runners by a wide margin, Mr Edwards attempted to rise above the acrimony while pleading for an equal hearing.
"Are there three people in this debate, not two?" asked the former North Carolina senator.
"We have got to understand, this is not about us personally. It's about what we are trying to do for this country."
The Republican presidential contenders, meanwhile, were focusing their attention on Florida ahead of the state's primary on 29 January.