Clansmen: Traditional Highland dress in a parade group line-up in Virginia. Picture: Donald MacLeod

AMERICA passed up on a grand opportunity in rejecting John McCain for George W Bush. War hero and reformer McCain may have been, but he was also palpably a Scot. With his back to the wall in Virginia recently, he told the Republican establishment to get shafted, in a speech which made the headlines for its sheer bellicosity.

"McCain says he had trouble his whole life keeping his throttle shut," as Time magazine observed. "The son of a line of Scottish warriors who turned up in the American Revolution, he emerges from a culture of men who can decant a string of salty oaths one minute and offer compassion the next." And who says cultural stereotypes are dead?

Donald Trump's mother Mary is Scottish - born in Stornaway, and a "great influence in his life", according to a considerate fax from the Trump Organisation. So is US comedian Jay Leno's wife, who has talked up his Scottish sense of humour, although Leno's father is Italian. The richest man in the world, Bill Gates, is a Maxwell on his mother's side.

About five million Americans, it is estimated, carry Scots ancestry, another five million if you count the Scotch-Irish. In fact, McCain was not the only honorary Scot in the Republican race this year. Publishing scion Steve Forbes, fond like his father Malcolm of sporting a kilt, came courting voters at the Grandfather Mountain Highland Games in North Carolina, the best-known such gathering in the country, held in a state famous for its Scottish roots.

Bagpipes, tartan, and whisky. Clan names, Braveheart and that distant Scottish ancestor. In many people's eyes, that about sums up the American experience of Scottishness, in a country where the best-known living Scot is undoubtedly Dolly the Sheep. American cities now host approximately 260 Highland games and festivals each year, during which "Culloden survivors" and "oatmeal savages" turn up in purple war paint and slinging broad swords. Visitors are invited to "find your clan".

But can Scottish America ever count for something more than a giant roots trip, with its vision of Scotland verging on a Disney theme park? On 6 April the third annual Tartan Day in America takes place, established by a Senate resolution sponsored by Republican leader Trent Lott, a Buchanan. It comes amid a surge in enthusiasm for things Scottish, and an effort by Scottish Americans who treasure their heritage to raise their profile.

Tartan Day - on the anniversary of the Declaration of Arbroath in 1320, which declared Scottish independence under Robert the Bruce - will be celebrated for the first time this year in the US capital, in a three-day Scottish festival a few blocks from the White House. With more events in Chicago, New York and many of the 50 US states, there are efforts to make Tartan Day a national party along the lines of St Patrick's Day. An idea that met much scepticism three years ago, it is now billed as the one day that the Scottish roots crowd, too, can indulge in a little ethnic frenzy.

Last month, the Scottish Coalition brought together seven leading Scottish-American organisations in Sarasota, Florida - groups representing the games, some of the 60 St Andrew's Societies, the 200-odd clans and charitable and business foundations. It marked the latest attempt to impose some coherence on the American Scots and build on the appeal of Tartan Day. It is time, some say, to seize an opportunity and mould the myriad clans, societies, Burns' Night gatherings and kilt-wearers of all ilks into a Scottish-American identity. Whether it can be done is an entirely different question.

Scotland the Brand, part of Scottish Enterprise and a leading backer of Tartan Day, laid on a reception at the Birdkey Yacht Club for the Florida gathering; there was a trip to the new Scottish Pavilion at the Epcot Centre. Duncan Bruce, whose book, The Mark of the Scots, has established him as a popular authority on the Scottish diaspora, delivered a lecture. There were forums on adding younger volunteers, and the impact of the next US census as a measure of American Scottishness.

The Irish-Americans have established themselves as a potent political, business, and fund-raising force in America, funnelling millions of dollars to Ireland each year, and this is bringing some longing looks from their fellow Celts. Alan Bain, chairman of the New York-based Scottish-American Foundation, which has set its sights on a $15 million Scotland House, says: "I recognise the Scots are not in the same position as the Irish, but there's no question that the support for things Scottish is there."

That message is echoed by Sharon Kennedy Ray, the editor of Highlander magazine, which has a paid subscription of 30,000 and is the largest US Scottish publication. "In general terms, the whole Scottish American movement is gaining momentum," she says. "There are all these disparate societies, and Scots being Scots, it's not very cohesive. But there is certainly a lot going on." America's recent interest in things Scottish has been fed more by Braveheart and other movies than devolution and the new parliament. Though both have at least put Scotland in the news, Americans, it is said, see nothing special in a Scottish legislature - with every US state, after all, boasting its own, along with an elected governor.

But the Highlander's forthcoming directory of Scottish America lists twice as many pages - 24 - of pipe bands than a year ago. One American band, the LA Scots, has reached the top grade in Scottish competitions for the first time. Twenty years ago, the American Midwest had two or three Highland games. Now it's more like 15, and nationally they run from Hawaii to Alaska. The St Andrew's Society of Illinois - one of about 60 in the US - recently sent out a mailing to a 17,000-strong sample of people in the Chicago area with Scottish surnames, a tiny fraction of the total number. It netted about 500 replies, a response rate which is unusually high in the world of marketing.

In the so-called Scottish diaspora - estimated by some counts as about 90 million world wide - sentimental interest in Scotland is on the rise. Take the gathering of Clan Fraser in 1997 at the castle owned and operated by the National Trust for Scotland. It drew 30,000 people, an estimated 12,000 from outside Scotland, including 1,500 from Canada and contingents from the US, Finland, Sweden, Russia and Malaysia.

Alex Beaton, the well-known solo artist who grew up in a piping family in Glasgow - who came to the US in 1965 and now lives in California - is one of the beneficiaries of the boom in Celtic music and highland games. He spends about half his weekends at some 24 festivals around the country, and is currently en route between gatherings in Arizona, and Florida. He intersperses his performances with chats about Scotland, and on demand will deliver Burns's Address to the Haggis at suppers. "It's great to see a lot of people proud of Scottish heritage, that are really into genealogy, and proud of it. It's great for Scotland because these people are all buying kilts."

Meanwhile, it is estimated that perhaps 30,000 Americans are active members of clan groups, some answering to Scottish Lords and others to no-one in particular, constantly forming and re-forming, often boasting more chiefs than Indians. Neil Fraser, a leading Canadian clan figure, has been in e-mail correspondence lately with the members of a newly formed "Clan MacLamroc" in North Carolina. He's failed to find the surname in Black's Surnames of Scotland, or in the Scottish and the Canadian telephone directories. "Where the hell it comes from, I have no idea ... this is a perfect example of the enthusiasm that Braveheart and these other movies have encouraged."

William Lindsay, the mysterious Las Vegas-based American who donated £1.4 million to Glasgow University last week, may be a member of the Lindsays, another large and active US clan group.

The Scots comprise some of the oldest, and newest, immigrant communities in America. In the southern society city of Savannah, Georgia, better known for its St Patrick's Day celebration - second only to New York - the St Andrew's Society was founded 262 years ago, before the American Revolution, a heritage celebrated in an annual black-tie dinner.

There were two early waves of immigration to the New World, say the experts: Gaelic-speakers who fled the Highland Clearances for the Carolinas, and others who headed for the eastern cities, followed by Scots-Irish, who flowed out of Ireland by the boatload, and apparently included McCain's ancestors. "The Scots were among the very earliest immigrant groups, so they have really assimilated," says Bain. "It is a distant memory, but it is a very real memory none the less."

The chief chronicler of the Scottish diaspora - though some cringe at the name, saying it should be for Jewish use only, under the dictionary definition - is author Duncan Bruce, and much in demand on the Scottish-American lecture circuit. He comes laden with fascinating facts - that the two leading prep schools in Chile are named St Andrews and there is a MacKay School, where students eat oatmeal for breakfast every day.

Bruce quarrels with those who think a Scot must be Scottish-born and bred. The Scots-Irish he claims as Scots, and in a forthcoming book on the 100 most influential Scots, he lists about half who were born outside the country. In the last US census, in 1990, samples indicated that about 4.5 per cent of Americans were aware of Scottish ancestry, he said, though 86 per cent of these, sadly, reported another ethnic origin as well.

North Carolina has one of the biggest early Scottish populations; Canada is much more Scottish and that influence has probably carried over to Maine. "The problem is bringing it together," says Bruce. "To reach the Scots you are going to go all over the place. They're spread out pretty thin. It doesn't mean they can't be reached."

The festivities in Washington next month run from an appearance by the Strathclyde Police Band, to a forum on "The Living Legacy of Scotland', with Scottish and American academics talking up Scottish America. It is sponsored to the tune of $20,000 by Euan Baird, the Scottish CEO of Schlumberger, the multi-billion, 64,000-employee technology company.

Baird is an ex-Aberdeen Grammar School pupil who divides his time between New York and Paris and is married to a Dane. "I go fishing in Scotland and play golf in Scotland," he says. "My wife calls it my emotional baggage. Just don't ask me to live there." The comment masks a commitment manifested in Scottish Knowledge, a technology venture he chaired in a bid to act as an "education broker" between science and business, in which Rupert Murdoch recently bought a quarter share.

"It's heartening and touching how well received Scottish people are in the US," he said. "But Scotland itself doesn't benefit from it." He echoes a common complaint: that each little organisation - whether a university, a clan, or a company - pursues its own variant on the Scottish-American connection, but that "all the different societies never talk to each other, don't exchange information, and as a result aren't nearly as effective as they should be." Creating a Scottish image, he says, has to be directed with a focus and a willingness in Scotland to harness that. "It can't be handled by ex-pats. There has to be a force from Scotland."

Modern Scottish immigrants are easy to find on a Friday night in LA, at the Cock'n'Bull Pub or McCabe's bar, both in Santa Monica, long the home of Hollywood's British contingent. "One of the popular misconceptions that people have back home," says Colin McCabe, bar owner and actor, "is that a son or nephew or grand-daughter living in America are on their own, totally isolated from their own culture." Like many other Scottish emigres, McCabe says: "I knew nothing about my heritage until I came here, and that's true of most people."

The Los Angeles contingent runs well beyond the likes of Sean Connery, or newer Britpack Hollywood types like Robert Carlyle, or Danny Boyle. The "Westchester Scots" meet every Thursday at the Westchester Golf Course. They drive and putt their way between the palm trees round a no-frills course in a distinctly unalluring quarter of Los Angeles, where golfers tee off to the roar of big jets on approach to the city's airport.

The Westchester Scots number about 25, all men, and mostly Glasgow lads made good. Some are refugees from Thatcher's Britain, a couple are fresh off the plane, and an older crowd arrived in the 1960s, when all it took to get a green card was $300 in your pocket. The night begins on the course, and ends at a long table at the local Mexican, with lottery tickets and a box of British newspapers.

It's not just about golf; it's about home. "They are on to you with that fake Scottish accent and about their great-granddad," says Laurie Slaven, summing up the immigrant's old curse of a funny name and a stranger accent. Slaven worked as a fisherman for 12 years out of Scottish ports; now he works in Los Angeles as a website developer. He used to take it personally when colleagues and clients could not, or would not, understand his speech. But in a company with 400 employees he says: "The funny thing is they all know who you are."

He's teamed up tonight in a four which includes Derek MacKay, a 28-year-old from Balloch, Loch Lomond, who caddies for movie stars and plastic surgeons at one of LA's smartest clubs. The tips run to rooms in Las Vegas - "it's got its wee perks", he said. Then there's Henry Watt, a Scot who has lived in the US for 12 years, who works in sales for Ricoh copiers. "There's an awful lot of us here," says Watt. "An awful lot of us."