As far as anyone is aware, Barack Obama has never exposed himself to the paparazzi, shaved his head to defy his mother, made a sex video, or been admitted to a psychiatric ward.

If you believe John McCain, however, it’s probably only a matter of time.

In perhaps one of the most bizarre election campaign ads of recent history, the 71-year-old Republican presidential candidate compares Obama’s global celebrity to that of Hollywood’s most notorious starlets: Britney Spears and Paris Hilton.

The message? ‘Obamania’ is just a passing media fad—and Obama himself just a fame-hungry diva, more interested in his close-up than, say, the policy details of drilling for oil on America’s Outer Continental Shelf.

McCain’s ad, entitled ‘Celeb’, is set to air in 11so-called ‘battleground states’. It intercuts images of Obama on his recent trip to Europe, where he was greeted like a rock star - or a 21st Century Messiah - with video clips of Britney and Paris engaged in typically frivolous, starlet-like behaviour. “He's the biggest celebrity in the world, but is he ready to lead?" asks the voiceover, ominously, before going on to suggest that the junior senator from Illinois is an inexperienced tax-raiser who can’t make the difficult decisions necessary to solve America’s energy crisis—ie, drill for oil in environmentally sensitive areas.

After initially greeting news of the ad with bafflement—getting ready to board a jet, Obama said, “You need to ask John McCain what he's for, not just what he's against”—his campaign staff retaliated with an ad of its own, dismissing McCain’s Britney analogy as “baloney” and “baseless”. The Obama ad shows images of the Arizona senator with President Bush and accuses McCain of practicing “the politics of the past”. It is expected to air as soon as today (Thursday).

It is the second Obama spot in as many days that has responded to so-called ‘attack ads’ by McCain.

The McCain camp’s strategy has at least succeeded in getting the media’s attention, something the Republican presidential candidate has failed spectacularly to do over recent weeks. But not everyone is sure it has worked in his favour. After all, say analysts, the ad runs the risk of portraying McCain as an curmudgeon—he’s 25 years Obama's senior—while at the same time pointing out Obama’s global popularity to US voters who are largely tired of being hated around the world.

Kathleen Hall Jamieson, a communications professor at the University of Pennsylvania, says the bottom line is that the comparison of Obama with Spears and Hilton is unlikely to change many voters minds about the Democratic candidate.

“The typical viewer will fail to see the analogy,” she said. “Voters believe Senator Obama is a celebrity, but not in the same sense as Britney Spears and Paris Hilton.”

Obama was said to be particularly baffled by the comparison with Paris Hilton, whose name he has often cited when criticising President Bush’s decision to raise the threshold for America’s inheritance tax. “The Paris Hilton Tax Break,” he frequently calls it.

But it’s nothing personal, apparently.

“I've never even met the woman,” Obama admitted yesterday.

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