It was the kind of glittering occasion at which John Kerry and his wife would feel at home. There were millionaires in tuxedos with their Botoxed and bejewelled wives, graceful daughters with flawless skin in evening gowns, members of the Kennedy and Hearst dynasties and, because this is New York high society, there were artists surrounded by their patrons and benefactors.

They had come to celebrate the National Arts Awards, but it was also the night of the final debate between Kerry and George W Bush. A special room was set aside for the dinner guests to watch the ding-dong on a big screen while eating petits fours and quaffing champagne.

Andres Serrano, the artist responsible for Piss Christ, one of the iconic images of the late 1980s culture wars, was rooting for Kerry. Wedged between two beautiful women, he enthused: “The debate’s going well. Kerry’s winning over the audience here.”

Indeed. There were laughs and applause for Kerry, groans for Bush. Jeff Koons, the celebrated pop artist, was standing by the bar. “There’s got to be a change for the future of the country,” he told me soberly.

Then Koons became unexpectedly open-minded. “This administration” — he couldn’t bring himself to say Bush — “has supported the arts. In this particular area, they have been generous.” But never mind such parochialism. “For the good of the country, it’s time for a change,” he repeated his mantra.

So here I am in deep Kerry territory, surrounded by designer Democrats who are far wealthier than me, harbouring a secret and deeply untrendy thought.

Darn them all, despite being a registered Democrat — and in my London days a staunch Labour supporter — I am going to vote for George Dubya.

When the metrosexual chap standing next to me confides that urban sophisticates prefer Kerry because “you have to have a low IQ to appreciate Bush”, I know I am making the right decision.

“The guy is an idiot,” he continued snobbishly. “I don’t know what the rest of the country is thinking.”

Perhaps I can enlighten him. I will be one of the millions voting for Bush because I trust the president’s judgment on the war on terror more than Kerry’s. In this election, I am a single-issue voter. It is that simple. Even in the New York metropolis, there are more of us out there than he imagines.

I have registered as a Democrat because I want to put the party on notice. Should it lose the election — an open question at present — I want it to look at the numbers of Bush-supporting Democrats and draw the appropriate lesson about its unconvincing foreign policy. Perhaps then I will be able to support the party in 2008.

My vote for Bush involves a fair amount of gritting of teeth. I am not a Republican and do not care much for the company he keeps. Back in Britain I have voted Labour since I was 18, sticking by the party through its wilderness years when it veered towards the extreme left.

I was political editor of the left-wing New Statesman magazine in the early 1990s when two bright MPs, Tony Blair and Gordon Brown, embarked on their quest to make Labour electable. They succeeded so brilliantly that Labour dominates the political landscape. If I could vote for Blair in the American elections, I would. Unfortunately his name is not on the ballot.