Rupert Cornwell: In Tony Soprano's home town, fat is a political issue

Out of America: US electors like their leaders to be svelte, but a TV ad attacking a portly candidate may have gone too far

Forget the healthcare fight, and forget Sarah Palin (who, in any case, has gone oddly quiet ahead of the publication next month of her autobiography, Going Rogue). To put it in non-PC terms, the most intriguing question of the hour in American politics is this: can a fat man be elected governor of a major state?

With its odd number, 2009 is an "off year" in US political parlance. Michael Bloomberg is running for a third time for mayor of New York City, but as an independent whose success or failure will say little about the standing of the two major parties; and a special Congressional election is being held in a rock-solid Democratic district close to San Francisco. But on election day, now barely three weeks away, on the first Tuesday in November, there will be only two state-wide contests: for the governorships of Virginia and New Jersey.

Their importance has been accordingly magnified. The results of both – and especially the vote in Virginia – will inevitably be taken as referendums on the first 10 months of life under Barack Obama, whose poll ratings have been dropping slowly but steadily since his inauguration in January. The omens in neither state are very promising right now for the White House.

Last year Obama became the first Democrat to carry Virginia in a presidential election since Lyndon Johnson in 1964 – extending a hot streak for the party after its capture of the governor's mansion and both the state's Senate seats. But Robert McDonnell, the strongly conservative Republican candidate, has taken a clear lead in the battle to succeed the outgoing Democrat, Tim Kaine. And this despite a flap after someone got hold of McDonnell's law school dissertation from 1989 in which he lambasted "co-habitators, homosexuals and fornicators".

The story has been much the same in New Jersey – these days a pretty reliable Democratic state – but where the incumbent governor, Jon Corzine, an ex-US senator and former CEO of Goldman Sachs, is trailing the Republican Chris Christie. Or rather Mr Corzine was trailing, until he started running a highly controversial ad against his – how shall we say it? – somewhat corpulent opponent.

Politics in New Jersey, land of the TV mobster Tony Soprano and of this summer's real-life kickbacks scandal involving mayors, government officials and even rabbis, has always been a grimy sport. It is, one local commentator wrote not long ago, "easier to climb Mount Everest in a wheelchair ... than clean up the government of Jersey City". But at least, he might have added, you didn't go after a guy, even a guy who's trying to grab your job, just because he's fat. That, however, is exactly what Mr Corzine did last week.

The ad ostensibly takes aim at how Mr Christie, when he was a federal prosecutor in the state, allegedly pulled strings to escape some traffic violations. But the real message is even more personal. The camera lingers on Mr Christie's ample girth as he manoeuvres himself out of an SUV. The sequence is shown in slow motion, making the man look plumper still. Just in case viewers still didn't twig, the voice-over accuses the Republican of "throwing his weight about" to obtain these favours.

Not surprisingly, the Republicans are furious, and ordinary voters profess to be shocked by such base tactics; whether the candidate is overweight or not, they tell pollsters, has nothing to do with his fitness for office. But the campaign seems to be having an effect. The contest is starting to tighten, and when focus groups are asked to describe Mr Christie, increasingly the first adjective to be heard is "fat".

Both of itself, and by extension, that is not good news for the candidate. By extension, because fatness, psychologists say, conveys the impression of a lack of discipline and self-control. But of itself also, because, even though 30 per cent or more of Americans may be classified as obese, fatness is a stigma. If it were not, why is it so hard to think of a single genuinely fat American politician?

Anyone who imagines that politicians here can still look like the jowly, dishevelled Charles Laughton playing Senator Seabright Cooley in Otto Preminger's film Advise and Consent, should think again. Once upon a time, the country did have a president, in William Howard Taft, who weighed 330lbs (23.5st) when he left office in 1913. Teddy Roosevelt certainly carried a few extra pounds, while Bill Clinton lost many a battle with fast food. Ted Kennedy often looked a bit plump, too, partly because he wore suits a size too small for him.

But while you could reproach George W Bush for many things, being flabby and overweight were never among them. As for the current occupant of the Oval Office, Barack Obama himself would remind us that he was the skinniest member of the Senate when he won in 2008. And his svelte, honed frame remains an unarguable political asset.

Mr Obama, moreover, is merely an extreme example. The majority of male US senators tend to have the bland interchangeability of TV anchors – tall, glossy, walking advertising boards for the miracles of cosmetic dentistry, and not the slightest trace of embonpoint (or, for that matter, almost any other distinguishing feature).

If you do happen to be on the rotund side, you try to correct matters. Bill Richardson, the governor of New Mexico, a contender for the Democratic nomination last year, has fought many a battle with his waistline. The real success story, though, is Mike Huckabee, who tipped the scales at 300lbs (21st) when he was governor of Arkansas. Then he was diagnosed with diabetes at the age of 48 and told he'd be dead in 10 years.

Huckabee not only shed 120lbs and wrote a best-selling book, Quit Digging Your Grave with a Knife and Fork. He also gave John McCain a run for his money for the 2008 Republican nomination, and, along with Ms Palin and Mitt Romney, is an early front-runner for 2012. Chris Christie could yet be on to a good thing.