The Regal Republic: Why are Americans obsessed with the Royal family?

Next week, an American friend is making the 400-mile trip from Washington DC to Wilmington, North Carolina for a wedding.

Given that the ceremony is taking place on the other side of the Atlantic at 6am local time, the invitees (for some reason, it is an all-female event) may be forgiven if they watch the exchange of vows on television en peignoir, before donning their finery for the reception at 11am. The menu might be described as Gone-With-The-Wind genteel: a mix of dainties ranging from cheese and raisin wafers and ham biscuits to cucumber sandwiches, strawberries and little cakes with caramel icing, washed down with champagne, white wine or southern iced tea. Dixie is always said to have had a soft spot for the House of Windsor.

The nuptials in question are, of course, those of Prince William and Kate Middleton. Our friend's odyssey is unusual, but hardly exceptional given the circumstances. If my own trip back to London this month is anything to go by, America is more into this wedding than even Britain. We've already had the made-for-TV movie William & Kate ("Do yourself a favour and stick your head in the oven," was one critic's advice to viewers). The morning shows have been in saturation-coverage mode for days now, while America's zillion-dollar television news anchors will be based most of this week in London. The rumour however is unfounded that the networks asked the Palace to push back the wedding to early afternoon to accommodate the US domestic audience.

Instead, hotels and restaurants in cities across the country will be holding pre-dawn (in the case of the West Coast, middle-of-the-night) parties to mark the event, live. And you may be sure that Wilmington is but one of dozens, probably hundreds, of private events taking place across the country on 29 April. All of which raises the question: why the fuss? Having gone to such lengths to break free from a British monarch 235 years ago, why are Americans so besotted now by the marriage of one of his distant descendants?

The obvious answer is our age's obsession with celebrity. The royals are the ultimate celebrities. They did nothing to earn it, they were born with it – which of course only makes celebrity even more potent. They are the supreme curiosity, famous because they are famous. In the giant Disneyland that Britain is for many Americans, the Royal Family is exhibit A. But there is more to it than that. For one thing, only in the closing stages before the War of Independence was the colonists' anger directed at George III; the government in London, not the King himself, was until then the object of their resentment.

Today the country sees itself as thoroughly egalitarian, but it might easily have taken another path. In the Republic's early days, some wanted to give the President the title of "His Exalted High Mightiness". Nonetheless, British royalty fills a gap in American life. True, the Kennedys are often described as America's royal family, but that designation owes almost everything to the style and grace of JFK (exceeding that of any real king) and to the tragically early death that elevated him to legend. In purely dynastic terms, the Bushes now out-do the Kennedys: a senator, two presidents and a couple of big-state governors, spanning three generations, surely trump a single President, three senators and a handful of congressmen covering only two generations?

But unlike the Kennedys – or even the Clintons – the Bushes have never quite hit America's royal sweet spot. The closest thing to a royal wedding here was not Jenna Bush's marriage in 2008 (when her father George W. was still President) but Chelsea Clinton's nuptials last summer, almost a decade after her father left the White House. And now, with Teddy Kennedy gone, and no sign of a successor in the next generation, the Kennedys face their own version of public extinction. In a decade or two, they may be no more than a folk memory, as remote from the present day as the Tafts or the Roosevelts.

Indeed, in a country where money is the measure of most things, America's nearest equivalent to royalty is perhaps to be found in business, not in politics; in dynasties like the Du Ponts or the Fords, and most obviously the Rockefellers – still still going strong five generations after Standard Oil was founded in the late 19th century, still unimaginably wealthy, and still dispensing vast sums to philanthropic causes, as if to atone for the ruthless means by which John D Rockefeller, prototypical robber baron, built his original fortune. Such is noblesse oblige in today's America.

But none of this is the real thing. The Kennedys, the Bushes, the Clintons, not even the Rockefellers – none of them function like "an intricate tapestry that hangs in the background of everyday events", to borrow the feliticious phrase of Raymond Seitz, the former US Ambassador to the Court of St James's. So when the Americans see the real thing they love it. And never more than now.

This is the right wedding, at the right time. For one thing, in the US as in Britain, these are tough economic times; a royal wedding is a splendid distraction. For another, the Windsors are on something of a roll here. Recent films such as Helen Mirren's The Queen and the Oscar-winning The King's Speech have been smash hits, above all because they de-mythologised the Royal Family by making it if not familiar, at least poignantly human. Both, too, have been reminders of the sheer durability of the monarchy, and of this monarch in particular. The little girl playing with her father in The King's Speech is the very same person who six decades later struggled in The Queen to respond to Diana's death – and who now, 14 years after that, is about to become grandmother-in-law to Kate Middleton.

During that time, Americans have avidly followed the dramas, the scandals and the pratfalls of her children and their spouses. But they also realise that the show has been kept on the road by the Queen's duteousness, her subordination of self to office, by her sheer professionalism. Apart from the Diana wobble in 1997, she has barely put a foot wrong. If she had, or had she died young, it is conceivable Americans might not even have a royal wedding to savour now.

As it is, the US has nothing to compare. The Queen inherits her job, but its head of state emerges from a cut-throat election process every four or eight years. At regular intervals the country must get used to a new President and First Lady. Queen Elizabeth II, by contrast, is on her 12th prime minister – and for that matter her 12th American president (though Eisenhower had taken over by the time of her coronation, Harry Truman was in the White House when she ascended the throne in 1952). In London and Washington, governments come and go, but thanks to the Queen, the British monarchy just keeps ticking away, like an ancient grandfather clock in the drawing room. Every now and then you check the movement; but otherwise, to keep the instrument looking its best, just a good polish is needed – and what better polish than a royal wedding?

This one, moreover, isn't just any royalwedding for Americans. To use that tiresome Americanism, it also offers "closure" of a kind to a royal drama matched in modern times only by the abdication crisis of 1936 (when this Queen's uncle gave up the throne to marry, you will remember, an American). When Americans think royalty, they still think Diana. Her own marriage in 1981, its tumultuous aftermath and then her death, transfixed them. Now the first-born son who looks so like his mother is marrying. Diana was never to be Queen; but in William the future King her destiny is to be fulfilled. On the other side of the Atlantic, this is the real storyline of 29 April.

Now none of the above is to suggest that the US is starting to wonder if it made a mistake in casting off the monarchy 235 years ago. Republicanism is in the country's official genetic code; one reason the constitution bars a president from seeking a third term is precisely to avoid infection by the royal virus. Americans like their presidents accessible, the sort of person you could have a beer with. They could not stand an office wreathed in pomp and circumstance, sealed off from the general populace, could they? The truth is, in many respects, that's what they've got.

Like it or not, a president is in part a king. He is the commander-in-chief. His motorcade is like an armoured regiment on the move, and the retinue that accompanies him on his foreign travels could be the mediaeval court during a royal progress. Unlike British royals, US presidents don't have to cope with phone hackers (secret Oval Office taping systems and unsuspected live microphones tend to be their nemesis). Even so, the gossip columns pick over the minutiae of a White House state dinner far more avidly than the British press would ever report on a Buckingham Palace banquet. Michelle Obama's wardrobe is accorded Diana-like scrutiny, the Queen's corgis are anonymous mutts comparedwith a US presidential pet. Buckingham Palace is an oasis of privacy compared with the goldfish bowl in which an American president lives.

Of course, he can't go too far: Richard Nixon, ever clumsy, made a fool of himself when he tried to introduce White House ceremonial guards in fancy tunics and toy soldier hats. But a president ignores the regal component of his office at his peril. Ronald Reagan understood that truth instinctively – indeed, by casting himself as disengaged king, he probably saved himself from impeachment in the Iran-Contra scandal. His predecessor Jimmy Carter went to the opposite extreme, presenting himself as a no-frills, no- formality Everyman, which may be one explanation why Americans never warmed to him.

And might not our fusty inherited monarchy, for all its scandals and silliness, these days have one other appeal? The Royal family may be dysfunctional on occasion, but at least its failings have purely entertainment value. And is it really more dysfunctional than America's elected governments, which actually have to run the country? In an age when US politics is so polarised that politicians can't even agree on where President Obama was born, let alone on action to tackle the country's fundamental problems, the notion of an unelected head of state, perched above the fray, is almost refreshing. Whatever else, you can't play party politics with the Wills-Kate union.

So the US, like Britain, plans to sit back and enjoy the show. But one final question remains: why the fascination with our royal wedding and not other people's? Ten months ago, the heir to the Swedish throne married a commoner. The roles were reversed; this time crown princess Victoria was marrying a man called Daniel Westling, her former fitness instructor. The couple were young and attractive, and royals from Europe and beyond attended the occasion in droves. The wedding procession was four miles long with a spectacular segment by royal barge across Stockholm's inner harbour. Yet Americans saw, heard and read next to nothing about it.

But then again, the US was never a colony of Sweden. The two countries do not share a language, nor did they fight against each other in the early 19th century, then alongside each other in most of the 20th and 21st century's great wars. Those are the links between America and Britain that underpin the transatlantic fascination with the Windsor/Middleton nuptials, beyond the simple enjoyment of a rattling good show. They explain in part why the ladies will be whooping it up in North Carolina next weekend. Indeed put these ties together – and you've got, well, a special relationship.