Something profound happened to the relationship between Irish Catholicism and politics last week. Joe Kennedy, scion of the family that embodied the tortuous relationship of Catholic Ireland to America, pulled out of the race for the governorship of Massachusetts.
He did so in large measure because of a book by his former wife Sheila Rauch Kennedy, Shattered Faith, which detailed the rather brutal way in which she was forced to accept the annulment by the Catholic Church of their marriage of 12 years.
For the first time since the 1950s a Kennedy has been, in effect, defeated in a Massachusetts election. And the defeat has been inflicted, not in a straight political fight, but by the strange contradictions that gather at the crossroads where sex, Catholicism, Irishness and politics all meet.
There is something oddly appropriate about the fact that what may be the last act of the great Kennedy saga has been played out as a sequel to a piece of internal Catholic Church business - the annulment of a marriage. For Catholicism has always been near the centre of the Kennedy myth.
It is hard, in the context of the Republic of Ireland, where orthodox Catholicism has tended to be identified with political conservatism, to remember just how politically disturbing the Kennedys' Catholicism was for America. While John F. Kennedy was president, the novelist Norman Mailer expressed the feeling that his Catholicism was almost in itself more significant than anything he might do with the job.
"With such a man in office," he wrote, "the myth of the nation might again be engaged, and the fact that he was a Catholic would shiver a first existential vibration of consciousness into the mind of the White Protestant. For the first time in our history, the Protestant would have the pain and creative luxury of feeling himself in some tiny degree part of a minority, and that was an experience which might be incommensurable in its value to the best of them."
The Kennedys' Catholicism, in other words, had the same psychic effect as Mary Robinson's femaleness had in Ireland 30 years later. Having such a president was, in and of itself, a form of change.
This was understood, too, by Kennedy's opponents, who used his Catholicism against him. The influential Protestant minister Norman Vincent Peale, for instance, claimed during the 1960 presidential election campaign that if Kennedy were to be elected the White House would be controlled from the Vatican. Later, when Kennedy visited the Vatican - shortly before his trip to Ireland - there was a huge volume of speculation as to whether or not he would kneel before the Pope and kiss his ring. (He didn't.)
There was, of course, a huge irony in all of this, for the Kennedy men, in their private lives, were not exactly strict Catholics. While Kennedy was preparing to meet the Pope, for example, the main preoccupation of his officials was not the protocol of kissing rings, but the arrangement of an altogether less formal pressing of the flesh.
The State Department was charged with finding him a beautiful but secluded place for a "private matter". The Villa Serbelloni on Lake Como had to be secured, cleared of its inhabitants, and prepared for the arrival of a "lady of some note in Europe". On the way to Rome next morning Kennedy told his Secretary of State, Dean Rusk, that he had an "absolutely wonderful" time. I doubt somehow that he told the Pope the same thing.
But even if he had done so, would it have mattered? For both the church and the Kennedys understood that in this context Catholicism was a political, not a moral, category. It was a tribal identity, sometimes, as in Ireland, almost a nationality.
When people talked of the Kennedys as Catholics, what they had in mind was not that they said the Rosary or used the rhythm method but that they belonged to an ethnic group that had, in Ireland and America, long been deprived of political power but that was now coming into its own.
The church would have preferred, of course, that the private morality was in keeping with the public identity. But given a choice between one and the other, it knew which was more important. If the condemnation of "sin" got in the way of the political prestige of having Catholics in great public offices, then the sin would have to remain uncondemned. If marriages had to be annulled, or if divorcees had to be remarried in church, then so be it.
At one level, of course, this was pure hypocrisy, no more or no less significant than any other kind of double standard. But at another, it also pointed to a larger and more profound set of contradictions concerning sex, religion and politics.
In the early 1960s Irish people were too innocent to even guess at what those contradictions might be. The Kennedys offered too much that Catholic Ireland needed - validation, self-confidence, some kind of assurance that the pain endured by an emigrant society would pay off in the end - for us even to contemplate the possibility that their personal lives might be less than saintly.
But as we grew up and needed the Kennedys less, we were able to see the gaps between image and reality. Strangely, the Irish became far more sophisticated than the Americans (or for that matter the British), far less inclined to expect political figures to be private paragons. In what is still a deeply Catholic country, we learned to leave the private morality of our politicians to themselves and their God.
Americans, to some extent, have been learning to do the same - otherwise Bill Clinton could never have survived. But the Kennedys, almost uniquely, continue to be judged by older standards. Catholicism remains a quintessential aspect of their public presence. And they are now paying for the church's grace and favour.
All those years of hypocrisy, of bending the rules to keep the Kennedys happy, are now coming back to haunt them. In a society where the personal is political, a chronic inability to respect women in private relationships is a political problem. And when there is a feeling that the institutional church has turned a blind eye to that problem it becomes, as Joe Kennedy has found to his cost, a huge barrier to public trust.
In that sense, Joe Kennedy's retreat marks a day in the death, not just of a dynasty that has loomed large in the modern Irish psyche, but of a certain kind of political Catholicism. Irish Catholicism is no longer in itself a sufficient political identity, either in Ireland or in America. To assume its aura is to be asked to be judged by standards of personal behaviour that are, for many, unsustainable.
That is why Irish politicians don't to it any more and why, after last week, no one in America is likely ever to try it again.