After a night when he had cast a long shadow over an acrimonious presidential debate Bill Clinton breezed into Lizard's Thicket diner yesterday claiming: “I'm not used to this — I'm a little out of practice.” And then he laughed.

The former President ate his breakfast of eggs and grits with some old friends — whom he just happened to meet — knowing that over the past fortnight he has successfully goaded his wife's chief rival for the Democratic nomination into a “fist fight”.

Barack Obama, who tried to present himself previously as someone who can heal or rise above political divisions, has now begun trading blows with Hillary Clinton and her husband.

At a televised debate in Myrtle Beach on Monday night he complained repeatedly that they were distorting his words and making statements that were “not factually accurate”, raising questions about their capacity for truthfulness that may have been a deliberate echo of successive scandals that dogged the Clinton White House in the 1990s. “We do have to trust our leaders and what they say,” Mr Obama added.

Over breakfast Mr Clinton protested his innocence. “There was nothing specific I said which was inaccurate. I try to be careful about what I say and not use too many adjectives.” Asked about the impact of his recent interventions in the race, he said that “it was the right thing to do” because of a need to counter “persistent and false criticism of Hillary”.

At one stage in the debate when Mr Obama again referred to the former President, Mrs Clinton snapped: “I'm here. He's not.” Her opponent responded sarcastically, saying: “Well, I can't tell who I'm running against sometimes.”

Yesterday Mr Clinton said: “I thought he was running against me in Nevada for a while when he said the Republicans had the ideas that challenged the conventional wisdom in the 1990s.”

Instead, he claimed that it had been his White House Administration with the new ideas on the environment, the economy and easing poverty.

The battle over the past triggered the most vituperative exchanges on Monday night as Mr Obama insisted that he had not praised Ronald Reagan or Republican ideas, saying he had been a community organiser in Chicago “working on those streets [when] you were a corporate lawyer sitting on the board at Wal-Mart”.

Mrs Clinton was a director of the controversial retail giant from 1986 to 1992 but has more recently returned donations from Wal-Mart, citing differences with company policies.

She came back with her own broadside, saying: “I was fighting against those ideas when you were practising law and representing your contributor, Rezko, in his slum landlord business in inner-city Chicago.”

This was a reference to Antoin “Tony” Rezko, a friend and fundraiser for Mr Obama. Prosecutors have charged him with fraud, attempted extortion and money laundering in a corruption case that has previously been largely ignored as an election issue. Mr Obama's campaign announced last week that it was giving to charity more than $40,000 (£20,000) from donors linked to Rezko.

Although the Reagan presidency is routinely lionised by Republican candidates these days, many Democrats continue to regard Mr Clinton as their saviour from a blighted era.

These include a large proportion of the black vote, who will account for half the turnout in Saturday's South Carolina primary but, with polls showing that Mr Obama has captured much of this community, Mrs Clinton has set her sights on “Super Tuesday” on February 5 when more than 20 states will hold nomination contests.

Yesterday she flew to California, where she was expected to receive the endorsement of the United Farm Workers Union, which represents many Hispanic workers who showed a marked reluctance in Nevada last week to support Mr Obama's bid to become America's first black president.

Mr Clinton has been left to carry on her campaign in South Carolina for the next couple of days and appears to be relishing the prospect. He said: “We're going to have a few arguments — this is a contact sport.”

On Monday night it had appeared to be more like tag-wrestling with John Edwards - who is placed third in the polls and was previously a sharp critic of Mrs Clinton — joining forces with her to make repeated twin-pronged attacks on Mr Obama.

Significantly, perhaps, the former President poured praise yesterday on Mr Edwards who, it is understood, had a 20-minute private meeting with Mrs Clinton after the debate.

Mr Clinton also adopted a more conciliatory tone towards Mr Obama, saying: “Sometimes when you have a family feud it's harder than when you have a feud with someone in

a different clan because you have to dig deeper to find where the difference is.”

During a calmer period of Monday's debate Mr Obama was asked whether — in the words of the author Toni Morrison — Mr Clinton had been the “first black President”.

He replied: “I would have to investigate more of Bill's dancing abilities and some of this other stuff before I accurately judge whether he was in fact a brother.”

Mr Clinton yesterday said that he loved the joke but might have to take some lessons, adding: “I just hope he gives me an age discount.”

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal