Philip Hoare: On the shores of Cape Cod, I see an America that is closing in on itself

The sense of derring-do and exploration which created America seems conflicted now

Surrounded by the sea, Provincetown sits at the tip of Cape Cod, held out into the Atlantic. It is both part of, and apart from, America. The philosopher Henry David Thoreau once said that here, "a man might stand and put all America behind him".

As such, it is a perfect place to observe the strange sense of stillness and inevitability with which the American people seem to apprehend the forthcoming and monumental change to their democracy. The greatest democracy in the modern world, all about to be reinvented, it seems, within 18 short autumn days.

These days of October have been blissful on the Cape. An unnatural warmth has settled over the place, the kind of heat we missed out on in Britain this summer. Last weekend was a holiday – Columbus Day, commemorating the discovery of a continent.

Half a millennium later, Provincetown, a former whaling port turned whalewatching port, a place of sunbleached clapboard and drifting sand on the pavements, is a resort for every creed, colour and gender. Currently celebrating Women's Week, it seems to encompass the liberty and hope of the once new republic. Black, white, straight, gay, transgendered and plain ordinary families – of the kind so appealed to by vice-presidential candidate Sarah Palin (just as the lesbian couples with their babies in designer buggies are most definitely not) – have been here, enjoying the last few days of an Indian summer.

Out on the whalewatch boats, the tourists ooh and aah at the leaping whales. Coach parties and groups of students, from places as far as the Midwest, listen to naturalists extolling the history of their country. "What they didn't teach you in history class – even if you were awake," Dennis Minsky tells them, "is that it was here that the Pilgrim Fathers first made landfall. Here, in Provincetown Harbour, the Mayflower Compact was signed." It's true enough: modern American democracy was born in these waters. This is were it all began.

Yet that sense of derring-do and exploration which created America seems conflicted nowadays. We Europeans bemoan the fact that 50 per cent of Americans don't even possess a passport. What would they make of the fact that a gentleman in his late 60s from Wisconsin, on his first whalewatch, asked me what a lobster was?

This week, I settled down next to my landlady's German shepherd, along with a representative focus group of Provincetowners, to watch the last presidential debate. I certainly don't hold out the company as representative of America as a whole. Comprising three artists, an historian and a naturalist, they were, to a man and a woman, Democratic-leaning liberals, ready to hiss at John McCain's strangely stilted delivery and to admire Obama's measured retorts and handsome mien. Even to an outsider such as myself, it was clear which of these candidates I'd trust with my governance.

Yet even the liberal pin-up boy Obama can get caught out. When McCain addressed the issue of free trade (on which he is very keen), he nodded, in his dismissive way, towards his fellow candidate and noted that Obama had "never travelled south of our border". "Ouch," said Dennis Minsky.

It may well be that we are seeing the closing-in of America. The financial crisis is set to turn the US's attention in on itself. What matters to the fishermen and whalewatch captains of Cape Cod is the fact that the price of fuel for their vessels has doubled in the past year. Both McCain and Obama argue for a self-sufficient nation. And employment and immigration are touchpoints. The old American values – and prejudices – are resurfacing. One old Provincetowner objects to "bums coming to town" and "spongeing". "If you want something, you work for it."

American students may fall asleep in history classes, but history is as important here – perhaps even more important – than anywhere else, precisely because it is still working out. America, as much as South Africa or any Baltic state, is still a work in progress.

A couple of nights ago I gave a lecture at the Fine Arts Work Center on Herman Melville's Moby-Dick. I delighted in pointing out the 150-year-old novel's prescience by reading from the first chapter, in which the protagonist, Ishmael, puts himself, self-effacingly, in the stream of greater history, much as Woody Allen did in his film Zelig.

"Grand contested Election for the Presidency of the United States ... Whaling voyage by one Ishmael" ... Bloody battle in Afghanistan." Melville's book was, even as he wrote it, an extended political metaphor. With the US on the brink of civil war over its own right, or otherwise, to keep slaves, Melville's paean to the great new industry of whaling – the first time America had made its mark on a global economy – saw the nice distinctions between different species of whales as an analogy for the raging debate over slavery and race.

The 19th-century whalers were the first to export American values around the world – tellingly, for purely economic reasons, rather than colonial ones. They were also pursuing an unsustainable resource – just as modern America has pursued the mineral oil that replaced whale oil.

Race, identity, isolation, adventure – these are the unwritten issues for America, as ever. In these final two weeks of the campaign, there's a definite sense that things are about to get vicious. It was chilling this week to see a Florida sheriff – in black uniform – stirring up a Republican rally with his stress on "Barack Hussein Obama". Hecklers have shouted "treason". At such moments, America can turn on itself with a savagery that evokes its beginnings, in the wilderness of this great continent.

You wouldn't know it, though, from Main Street, New England. This morning stormy clouds blew in from the Atlantic, muddying yesterday's blue skies. The gulls wheel overhead, and the shore birds, like the humpback whales, are getting ready to move to warmer, calmer climes. Unlike Senator Obama, they've been south of the border before. When they return next spring, America will have changed, irrevocably.

Melville's book concludes with the line, "the great shroud of the sea rolled on as it rolled five thousand years ago". So too these abiding shores, ever shifting but ever the same, will still be here, waiting patiently for the next tide to roll in.

Philip Hoare's most recent book is 'Leviathan, or The Whale', Fourth Estate, £18.99.