The race for the White House descended yesterday into a bout of playground taunts, cosmetic outrage, internet smears, and a blizzard of negative advertising designed to play on voters’ fears.

Barack Obama spent much of the day defending himself against charges of sexism after a speech decrying Republican efforts to present themselves as agents of change. “You know, you can put lipstick on a pig,” he said on Tuesday to loud cheers and laughter, “but it’s still a pig.”

John McCain’s campaign said that this was a clear reference to Sarah Palin, the vice-presidential nominee, who told the Republican convention that the only difference between a “hockey mom” such as herself and a pitbull terrier was lipstick.

The comment dominated news coverage yesterday, much to the dismay of Democrats who are desperate to regain the initiative after spending almost two weeks watching Mrs Palin bask in the spotlight of the media – and the attention of voters.

Mr Obama complained that Republicans had taken an “innocent remark” and turned it into a “made-up controversy” to distract the electorate. “This whole thing about lipstick, nobody believes that these folks are offended,” he told a rally in Virginia. “I love this country too much to let them take over another election with lies and phoney outrage and Swift-Boat politics. Enough is enough.”

His reference to the Swift Boat Veterans for Truth, which four years ago created a month-long frenzy with false claims about John Kerry’s Vietnam record, reflects the Democrats’ concern that Republicans have once more seized control of the election agenda.

Aides have spent 24 hours pointing out that “lipstick on a pig” is a phrase commonly deployed in politics, and have cited no less than five examples of Mr McCain himself using it. They said that the outcry was a “pathetic effort to play the gender card”. Some Democrats concede privately that Mr Obama’s choice of words was crass at a time when Mrs Palin’s lipstick joke was being replayed endlessly on news channels.

As the former Massachusetts Governor Jane Swift said at an inaugural meeting of the Republican Party’s “Palin Truth Squad”, only one candidate in the presidential race wears this form of make-up. She later added, less plausibly, that another line in Mr Obama’s speech had been a sly dig at 72-year-old Mr McCain. The Democratic nominee said that if an old fish was wrapped in a piece of paper called change, “it’s still gonna stink”.

Mr McCain and Mrs Palin held one more rumbustious rally together in Virginia yesterday before the Alaskan governor flew home to a triumphant welcome, a two-day profile interview with ABC News and the chance to say goodbye to her telegenic soldier son before he is sent to Iraq.

Her arrival at Fairbanks Airport was given the sort of treatment usually reserved for the Pope - and rarely, if ever, for a vice-presidential pick. Cable TV networks breathlessly reported scenes from the empty tarmac as they waited for her plane to touch down.

Mrs Palin spoke briefly, with the help of a teleprompter, to describe to the crowd her "amazing couple of weeks" and add: "I knew the coolest state would give us the warmest welcome." Her remarks were broadcast in primetime on the West Coast.

Mr Obama last night appeared on the David Letterman show where he acknowledged "she has been a phenomenon.” He mocked his own suddenly falling star, saying: “I mean, as somebody who used to be on the cover of Time and Newsweek, those were the days, I had a recent offer with Popular Mechanics, centrefold with a wrench."

A Republican advert claimed that Mr Obama had “air-dropped a mini-army of 30 lawyers, investigators and opposition researchers” – depicted as a pack of wolves – “to destroy” Mrs Palin. Another McCain campaign advert highlighted Mr Obama’s lipstick remark, saying: “Ready to lead? No. Ready to smear? Yes.”

Mrs Palin has undoubtedly been the subject of extraordinary allegations which have circulated widely on the internet. These include invented quotes in which she suggested that 4,000 years ago God had created “Satan’s Lizards”, or dinosaurs, so that America could have oil. Another falsely alleges that she used a racial epithet to describe Mr Obama.

Although there is scant evidence linking any of these claims to Democrats, the last week has seen a dramatic escalation in the number of attacks from both sides – and in the amount of mud being slung. Polls showing the two campaigns statistically tied have made the election taut with tension.

Yesterday Mr Obama’s team denounced as “shameful and downright perverse” a Republican advert accusing him of backing sex education for children “before they can read”.

But Joe Biden, Mr Obama’s running-mate, was accused of having “sunk to a new low” after referring to Mrs Palin’s fifth child, born in April with Down’s syndrome, when he asked at a rally: “If you care about [children with special needs], why don’t you support stem cell research?”

He later told a Chicago fundraising event that there was still “a lack of ease about Barack” among white suburban voters, Jews and Catholics. And yesterday he conceded that Hillary Clinton might have been a better vice-presidential pick than him.

"She’s easily qualified to be vice president of the United States of America, and quite frankly, it might have been a better pick than me," he said. "I mean that sincerely, she’s first rate, so let’s get that straight."

A Washington Post-ABC News poll this week showed white women swinging hard against the Democratic ticket with an eight-point lead being transformed in the space of a week to a twelve-point deficit.

Leon Panetta, a former Chief of Staff in the Bill Clinton White House, is among the senior Democrats who believe that Mr Obama has responded badly to his opponent’s surprise choice of running-mate. “They seem to be intimidated by the Palin pick,” he told the New York Observer.

The Clinton camp has urged Mr Obama to concentrate its fire on Mr McCain and avoid alienating women by launching attacks on Mrs Palin. Today, the Democratic nominee will end months of tension with the former president by sitting down with him for lunch – and possibly some advice.

Putting lipstick on a pig — who said it first?

“You can put lipstick on a pig. It's still a pig”

Barack Obama, on Tuesday, on John McCain's campaign adopting his “change” mantra

“I think they put some lipstick on a pig, but it's still a pig”

John McCain, in October 2007, on Hillary Clinton's healthcare plan

“John Kerry tries to put a bunch of fancy, fancy talk . . . but there is nothing you can do to really - to really obscure that record. You can try, though . . . We call it putting lipstick on a pig”

Lynne Cheney during the 2004 presidential campaign

“Mr President, it's not that easy. This town is full of people very experienced when it comes to putting lipstick on a pig”

GOP Senate Majority Leader Mitch McConnell on Washington in April 2004

Source: Times archives

The politics of swine, painted or otherwise, also featured prominently in the last British general election. Alastair Campbell, Labour's spin guru, famously produced a poster mocking Tory spending proposals and depicting the faces of Michael Howard and Oliver Letwin on the bodies of flying pigs with the phrase “The day the Tory sums add up”. Both politicians are Jewish, prompting cries of anti-semitism.

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