The most coveted invitation for most American high school students in 1977 was a free ticket to a Led Zeppelin concert. If you attended the National Cathedral School in Washington DC, though, it was an invite to a Saturday afternoon game of tag football at the Kennedys' home. Senator Ted, whose children, Kara, Teddy Jr and Patrick, attended our school, presided over a vicious game that made no allowance for either our youth or the awe he inspired in us: even in the most impromptu of scrums, the clan could not mask its competitive instincts. Not that we cared if we came away from the McLean compound black and blue and sore - spending an afternoon with the Kennedys gave us kudos and made us cool. Joseph Kennedy Sr may have been involved in murky dealings during Prohibition, but his descendants - the various Josephs, Bobbys, Carolines and, above all, JFK Jr - have become the royals of the United States.
Though as hereditary as the Windsors' monarchy, the Kennedys' is wholly American in style. Its heirs were - and are - expected to muck in at every opportunity in the life of the nation: during summer holidays the multimillionaire's progeny, like all American high school and college students, take paid employment. Even if they don't wait on tables at a greasy spoon cafe but get the more glamorous work of fetching coffee for reporters at a radio station, the Kennedy youngsters sample nine-to-five life and get to know their local community. Whenever there is a political campaign under way, you will find a junior Kennedy volunteering his or her services for the Democrat candidate (who, often enough, is some not-so-distant relative such as Joseph Kennedy Jr or Sargent Shriver); and some of the clan are full-time do-gooders, involved in the creation or running of nationwide programmes for the underprivileged. In this way the Kennedys' lives are woven into the fabric of the nation: they are not bicycling monarchs but stakeholding ones.
Yet, for all this standing shoulder-to-shoulder with ordinary citizens and posing as one of us, the Kennedys recognise that they are different - and must remain so. Americans need a royal (not just a first) family to aspire to: in a nation increasingly disenchanted with politics and elected politicians, here is a bright and beautiful personification of political ideals (spotlessly liberal) and private convictions (patchily Catholic). Privilege, the clan was taught, even before Tony came to power across the pond, comes with responsibility. JFK's stirring words - "Ask not what your country can do for you; ask what you can do for your country" - spell the difference between the noblesse oblige that, even post Diana, colours all the Windsors' activities and the total immersion of the man (JFK Jr) who created the magazine George or the woman (Eunice) who set up the Special Olympics for the disabled.
What explains the survival of the Kennedy magic? Nostalgia, I think. Say "Camelot" and most Americans will remember a booming economy unchallenged by either EU allies or Asian tigers, an invincible military power as yet untainted by the ignominy of the Vietnam campaign and a youthful and charismatic president whose unashamed patriotism inspired, rather than irked.
Camelot was the last time Americans were romantic about America. The Kennedys - Hollywood handsome but more accessible than any movie star; born with a silver spoon in their mouth but as doomed as a Greek tragedy - allow a little bit of the romance to continue. The disappearance of JFK Jr, in flight and over the sea, like some latter-day Icarus, simply adds another chapter.
For Democrats the family magic is all the stronger because, after the second Kennedy assassination, their party remained out of power for 20 of the next 24 years. And since then, a president who seemed to have inherited the Kennedy magic has merely proved pock-marked by their flaws.
Drink, drugs and women: the flaws have resurfaced so consistently in each new generation that they seem part of the genetic make-up. Yet despite presidential promiscuity, date-rape allegations, Chappaquiddick and at least one death from drug overdose, the clouds never quite dim the glamour and charm of Joseph's descendants. Their big money, powerful office and good looks have been perfect paparazzi fodder; this in turn has ensured, in a nation hooked on celebrity, their A-list status. So Ted Kennedy stalks the Senate corridors with the leonine gravitas of a Caesar; any candidate bearing the Kennedy name will command attention and, in their native Massachusetts, voters' loyalty; and, until his untimely death, JFK Jr found the doors of any media and advertising tycoon open to him and George.
The Kennedys seem at ease with this superstar status: they are given neither to the sulking of Prince Charles or the exhibitionism of Margaret or Fergie. Unlike the Windsors, they exhibit no anxiety about their perch being precarious or their brief redimensioned.
They may be the people's princes, but their influence and wealth are independent of the people's whims. Indeed their self-confidence is such that when Ted Kennedy Jr, still a teenager, lost a leg to cancer, I remember how he would swagger into our school parties, flashing his all- American smile, then sit down and remove his prosthesis, to a chorus of oohs and ahs from the young women who inevitably surrounded him. It was a truly extraordinary sight: a young man who could have felt cursed by his handicap, turning his prosthesis into a babe magnet. Only a Kennedy . . .