Why, some ask, should we grieve for this rich son of an irrelevant family?

IT WAS a benevolent fate that decreed John Kennedy Jnr's demise in the time of Bill Clinton. Under another president, under Ronald Reagan, George Bush, or Jimmy Carter, even under George Bush Jnr or Al Gore, the death of JFK Jnr would hardly have had the resonance it has in America today, and certainly not the capacity to generate such a mood of national mourning and regret for what might have been.

When President Clinton spoke, as he did yesterday morning at a reception for the victorious US women's soccer team, of this being a moment when "we really stop to recognise that, as big and diverse as our country is, we can come together as a national family", he was reflecting a sentiment that nearly all Americans seemed to share.

As with the untimely death of the Princess of Wales almost two years ago for Britain, the death of 38-year-old JFK Jnr and his 33-year-old wife caught a moment when currents of generations and social and political trends all came together as neither before nor since.

For Britain, the public outpouring of grief marked the passing of a certain idea of the Royal Family; it sealed the decline of the stiff upper lip as the defining feature of Englishness, and it seemed to sanction a change in the role of women, who saw in Diana's unhappy marriage and fulfilled motherhood a mirror of their own experience.

There is a similarly unique criss-crossing of strands in the United States now. Those in the prime of their power and influence, driving the Kennedy nostalgia, are the JFK generation.

The politicians are those, like Bill Clinton, who remember the exhilaration of John Kennedy's election and the promise it held. They are the generation that remembers the shock of his assassination, and recall their hopes, dashed again, five years later, with the killing of the heir apparent, his brother, Robert.

The luminaries of the media are those who cut their teeth as junior reporters at those events. And their audience is anyone in their late 30s or older, who remembers the heartrending pictures of the fatherless Kennedy children as they grew up, or who grew up with parents comparing their good fortune and progress with that of their Kennedy contemporaries.

The personal reminiscences of John Kennedy Jnr's college contemporaries - like the international reporter Christiane Ammanpour - who have paid their personal tributes to him over the weekend as an unaffected friend and engaging character are among them.

But so, too, are less privileged members of their generation. "You have to understand, I grew up with John-John", or with Carolyn, were sentiments heard frequently from their contemporaries as the news of his death sunk in yesterday.

The youth of Bill Clinton when he was elected to the White House, and the revival of racial and healthcare equality as political concerns at the start of his presidency all reinforced - with however little justification - the feeling that the hopes of the Kennedy administration, with its civil- rights priorities, could be revived.

And, while the actual course of the Clinton presidency looks likely to leave Americans less equal economically than when Bill Clinton came to the White House, Mr Clinton has reached out to black and poor Americans in a way that no other president since JFK has done.

With the emergence of JFK Jnr to prominence in Manhattan, a financial - but above all, a social - success, the Kennedy myth gained a new foothold with a different social group and a new generation. He and his glamorous wife, Carolyn Bessette, reflected - as the pile of flowers and tributes outside his home testifies - a fellow feeling among younger Manhattanites that here was someone like them, just richer, more successful, and "better".

Like his late father, John Jnr was able to bear the glitz that attended social success without giving the impression that he had lost his concern for the less fortunate.

John Kennedy Jnr's death also comes at a time when much of the negative baggage that the family name carried has been dissipated. The recklessly fast living of his father behind the scenes of the White House has been at least partly neutralised by the Oval Office exploits of Bill Clinton.

More significant, perhaps, is the passing - with the older Kennedys, perhaps - of the pervasive suspicion of the family's Catholicism and its Irish immigrant origins that attended John Kennedy's presidential campaign and supplied fuel for his political enemies.

That JFK Jnr is the scion of a Catholic family or of Irish descent has almost not been mentioned in the outpouring of sorrow and reminiscence. For this generation, the Kennedys are Americans; they are people of "strong faith", but the nature of that faith is now almost immaterial.

As with the mourning for the Princess of Wales, the moment when all the propitious currents converge is short and unlikely to be repeated. Already, in the views of the 10 per cent or so of Americans who look askance at the shock and grief attending JFK Jnr's death can be divined the end of the Kennedy mystique.

If the suspicion based in the religion and immigrant origins of the Kennedys is no more, there is a new wariness of their prominence and continuing influence as America's self-styled "royal family". Such sentiments are concentrated among those who are too young to have any recollection of the JFK years and no reason to identify themselves in any way with his children. They are concentrated among those in poor or minority districts who see little prospect of escape.

But it is also expressed by young meritocrats, who see the Kennedy clan as irrelevant, and see JFK Jnr as a young man of privilege who would not have got where he got without his name and fortune. Some of this hostility could be felt when the Pentagon called a press conference to report on the air-sea rescue effort, just hours after the plane was reported missing.

The younger reporters pressed for any hint that the extensive rescue effort was out of the ordinary and unwarranted, driven by the Kennedy name and celebrity.

Some of it is being expressed - in the newspaper correspondence columns, but above all over the Internet - in response to the media's saturation coverage of JFK Jnr's death. Some comments were so virulent that Internet services saw fit to excise them.

In this primitive debate about the significance of John Jnr can be heard the voice, and priorities, of the post-Kennedy, post-Clinton generation. We can expect that the anniversary of JFK Jnr's death, like the first anniversary of Princess of Wales's death, will be but a faint echo of the national mourning now in progress; that it will be so faint as hardly to warrant the description "national" at all.