As Edward Kennedy was laid to rest yesterday, accompanied by a further fusillade of eulogies, we were forcibly made aware, once again, of the American fixation with the idea of personal redemption. The British are a less forgiving people. While even the right-wing US press skated around the late senator’s appalling personal behaviour over many years, in this country even politically sympathetic newspapers published excoriating accounts, concentrating on the incident 40 years ago when the 37-year-old Ted Kennedy abandoned Mary Jo Kopechne to die alone in a car he had driven off a small bridge linking Chappaquiddick to Martha’s Vineyard.

It was only in a British newspaper that the American author Joyce Carol Oates was able last week to publish the following (factually accurate) account: “Kennedy chose to flee the scene leaving the young woman to die an agonising death, not of drowning, but of suffocation over a period of hours. It was over 10 hours before Kennedy reported the accident, by which time he’d consulted a family lawyer. The senator’s explanation for this unconscionable, despicable, unmanly ... behaviour was never convincing.”

As Oates might have gone on to remind us, Kennedy’s subsequent broadcast in which he sought to keep alive his political career was a staggering display of self-pity from which even his illustrious team of speechwriters could not preserve him; and although he paid $90,000 out of his own ample pocket to the parents of Mary Jo, her mother later recalled: “I don’t think he ever said he was sorry.”

If the Kennedys are the nearest thing to a royal family in the United States, they have almost divine status in Martha’s Vineyard (where President Obama delivered his initial eulogy last week), and so the Massachusetts senator easily avoided the prison term that would have been inevitable had the driver been any other drunk called Ted.

The man whose obituaries extolled him as the nation’s most skilful, experienced and determined legislator had good reason for acting as if he were above the law; after all, as a wealthy young man he had been expelled from Harvard for bribing a fellow undergraduate to take one of the more difficult exam papers for him, only later — against all precedent — to be readmitted. The poor sap who had done his dirty work was not so fortunate.

Yet it would be completely unfair to denigrate Kennedy’s subsequent record as a legislator on the basis of the manifold sins of his private life. When The Washington Post acclaimed him last week as “the champion of the poor, the downtrodden, the weak and dispossessed ... the causes of civil rights”, this was not mere post-mortem sentimentality: Kennedy did indeed have an extraordinarily faithful record in defending the interests, as he saw them, of the most deprived — a faithfulness that he seemed almost pathologically unable to provide in his personal affairs. The same man who treated women with abominable callousness (Kopechne was the least fortunate) was genuinely committed as a legislator for women’s rights.

It would be simple to dismiss this sort of behaviour as mere hypocrisy; but that would be to suggest Kennedy was not genuinely moved by the plight of those whose struggles he embraced on the political stage. He clearly was so moved. Nor was this solely motivated by a desire for the political limelight; he devoted an astonishing amount of time, year in, year out, to obscure back-room negotiations to try to win Republicans over to the merits of his legislative proposals.

So if hypocrisy can be dismissed as too crude an analysis of the Ted Kennedy phenomenon, what other explanation can there be for this extreme disjunction between private vice and public virtue? Although we can all think of right-wing politicians down the years caught out in sexual conduct that they have condemned in others, Kennedy’s particular pattern of behaviour is more characteristic of the left.

The most notable exponent of this was the man who almost invented socialism, Jean-Jacques Rousseau. He declared, “I am the friend of all mankind”, but treated his wife and children with revolting heartlessness: he ordered her to send one after another of the infants she produced to institutions where two-thirds of those committed never reached their first birthday. Rousseau, who was at least honest about his own behaviour, wrote: “How could I achieve the tranquillity of mind necessary for my work, filled with the domestic cares and the noise of children?”

He believed the task of improving the lot of humanity absolved him from the need to nurture his own family. Dickens, with his unerring eye, characterised this moral delusion in Bleak House in the person of Mrs Jellyby, so devoted to the cause of starving Africans that she had no time for the care of her own children: the consequent wretchedness of their plight scarcely crossed her mind.

A recent, entirely non-fictional example of what we might call Rousseau-Jellybyism is the case of Arthur Miller. When the playwright died in 2005, one noted obituarist described him as “the moralist of the past American century”, while The New York Times acclaimed this man of the left’s “fierce belief in man’s responsibility to his fellow man”. Yet two years after his death it was revealed that in 1966 he had committed his newborn son Daniel, who had Down’s syndrome, to an institution — one that someone who worked there at the time described as “not a place you would want your dog to live”.

It is true that this was a time when many people would have done the same, but what made this case especially vile was not just that Miller was supposedly a very enlightened man, but that his wife, Inge, had made desperate attempts to persuade him that they should keep their vulnerable child. Every Sunday Inge went to visit Daniel in the room he shared with up to 40 other children, but Miller never did. The great playwright wrote Daniel out of his life. His existence did not even get a mention in Miller’s memoir, Timebends.

Again, I would not say that Miller’s despicable treatment of his own flesh and blood discredits his work as a writer — the power of his depictions of emotional suffering and alienation remains and future generations will learn and benefit from them, even in the knowledge of the author’s own inability to live up to the standards he demanded of others.

It is, above all, naive and even childish to believe that those who achieve great things are men and women of less than normal human frailty. History — that is, real history — shows us that the greatest heroes are often spurred to their achievements by an insecurity and inner inadequacy that can be assuaged only by their taking on tasks which better-balanced personalities would regard as too risky, or even lethal.

It is in that context that we might view Kennedy’s run for the presidency in 1980. Probably he believed he would be shot, if not as a candidate, like his brother Bobby, then certainly as president, as Jack had been. In the event, he was scuppered early on by a television interview in which he floundered and stammered helplessly when asked why he should be considered as presidential material given his behaviour at Chappaquiddick little more than 10 years before.

The problem was that even if Ted Kennedy’s conscious motive had been to redeem himself, or his family’s reputation, he could hardly have said so without appearing to define his fight for control of the White House as a gruesomely public display of emotional neediness. Yet that was the story of his life.

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