Non-partisan fact-check operations, newspapers and opinion columnists are also charging McCain, once a darling of the press, of cloaking the election in sleaze and unfairly smearing Democrat Barack Obama.

With the United States locked in two foreign wars, punished by its thirst for Middle Eastern oil and with the economy plummeting, the race was consumed for two days last week by McCain camp claims Obama called Palin a “pig.”

US election campaigns and hardball advertising always push the limits of truth and often amount to outright distortion — the Obama camp has not hesitated to blur McCain’s record too.

   Cartoon — By David Horsey

Campaigns and experts usually steer clear of blatantly accusing a candidate of lying, but the term is being bandied about following McCain’s latest hard-hitting assault on Obama’s character and defense of Palin’s record.

Last week, the McCain campaign accused Obama of wanting to teach sex education in kindergarten. In reality, the bill he voted for as an Illinois lawmaker mandated warnings for young children about sexual predators.

Palin was accused of saying she visited Alaskan troops in Iraq when it emerged her trip was to an Iraq/Kuwaiti border post.

She is also taking heat for repeatedly saying she blocked a notorious multi-million dollar project to build a bridge to a sparsely-inhabited island in her state which she initially backed and of not fully returning all the federal dollars doled out for it.

“Generally those come out as outright lies, not just not incorrect,” said Larry Powell, a professor of communications of the University of Alabama at Birmingham.

The McCain camp is also now being accused in news reports of embellishing attendance figures at campaign rallies.

The Obama camp derided the volley of accusations as “disgusting lies” and questioned McCain’s honor.

Newspapers and independent fact-checking groups also accused Republicans of peddling untruths.

“The claim is simply false,” said FactCheck.org of the sex education ad.

The St Petersburg Times complained: “McCain’s straight talk has become a toxic mix of lies and double-speak.

“It is leaving a permanent stain on his reputation for integrity.”

Republicans, like President George W. Bush’s guru Karl Rove, have been playing hard knocks-style politics for more than 20 years, often taking a Democrat’s perceived strength and turning it into a liability.

Ironically, McCain was a victim of such treatment, bowed out embittered by the 2000 primary campaign against Bush and apparently not willing to take the high road again.

Governor Tim Pawlenty of Minnesota Sunday said Democrats were descending into “hysteria.” Another top McCain aide Carly Fiorina said McCain’s foes were panicking and accused them of unfairly exploiting McCain’s age.

McCain himself denied on Friday that his attacks were rooted in untruth.

“Actually, they are not lies,” McCain said on the ABC show “The View.”

“This is a tough campaign.”

Whatever its morality, the final judgement on McCain’s strategy will be dictated by whether it works.

An earlier negative barrage that branded Obama an empty “celebrity” seemed to jolt the Democrat last month, changing a race McCain appeared to be losing.

Latest broadsides slowed Obama again: for every hour he spends defending himself, he is not talking about the failing economy or comparing McCain to Bush.

“They are trying to put Obama on the defensive… to make a whiner out of him,” said Powell.

Latest polls give McCain a slight edge, but can a scorched earth policy work all the way through to November 4?

“If that is the only thing they are doing, then they would be in serious trouble,” said Kathleen Kendall, a communications professor at the University of Maryland.

“A lot of things are happening at once,” she said, mentioning positive advertisements the campaign is running and speeches by McCain on issues. Palin is also reinvigorating Republicans.

Obama’s response is also critical.

“I love this country too much to let them take over another election with lies and phony outrage,” he said before launching a fight-back.

But he does not seem comfortable in the political gutter.

“He doesn’t want to go as sulphorously negative as his opponents are if he can avoid it,” said Bruce Buchanan, of the University of Texas at Austin.

McCain’s aides are like “guerrilla fighters fighting those who are following Marquis of Queensbury rules,” he said.