Northern Ireland has never been any sort of agreed society. Nationalists felt disaffected and unwelcome, and there were always plenty of people like Ian Paisley to reinforce that feeling of alienation. With today's vote it may take a step in the direction of becoming a civil society rather than a tribal entity.
There is much sectarianism and tribalism and fierce mistrust. More than a few people feel unable to relinquish the old model in which incompatible ideologies remain locked in interminable conflict. You can see it in their eyes: that excited gleam when their side scores, the glumness when the other side scores a goal. This is politics as a football match, with added violence.
As of today, however, new models are on offer. The tribal model will still be there; a Unionist majority pitched against a Catholic minority. But there is also going to be a new civil majority, consisting of the people who will put this referendum through. They include almost all Catholics and a substantial number of Protestants.
There will also be an all- Ireland model, for the fact that the south is voting too, and will overwhelmingly vote "Yes", will provide an island-wide endorsement of the Good Friday agreement. To that can be added the important international dimension - Bill Clinton taking a personal interest in urging a fresh start.
Then there is the Blair dimension. Margaret Thatcher was passionate about Northern Ireland, but only sporadically; John Major had a deep interest, but lacked the political strength to act with real boldness. Tony Blair has sustained determination, an extraordinary attention to detail and an eye for the big picture. His campaigning zeal has undoubtedly added many points to the "Yes" vote.
The changes which are on the way are being eagerly embraced by the Catholic community, whose communal experience in the old Northern Ireland has left it hyper-politicised, with a great appetite for innovation and a great relish for politics.
Gerry Adams sits in west Belfast, preparing for government, having led a republican movement profoundly steeped in militarism to the point of participation in a new Northern Ireland administration. That transition to the purely political will take years to complete.
But a historic start has been made, and in this seismic shift he has brought almost all his people with him, shedding along the way only a few splinters rather than splits. More than 90 per cent of his people, and those of John Hume, will today be voting for the Good Friday agreement.
The importance of this change in nationalist attitudes has been obscured by the recent concentration on the divisions within Unionism, as that community faces a painful defining moment. The pace of the coming change will be influenced but not controlled by the outcome of that internal strife and the size of the "No" vote.
The referendum is going to pass in Northern Ireland; with virtually all the Catholics and nationalists on board, the main point of uncertainty is how many Protestants are going to vote "Yes". Whatever the figures the internal civil war is set to continue since the Rev Ian Paisley, whatever else he is, is certainly not a quitter.
The assembly is going to witness bitter scenes, since such institutions provide great opportunities for Paisleyite histrionics. His Democratic Unionist Party glories in conflict and accepts religious apartheid as the natural and indeed preferable order of things, opposing both social and political reconciliation. Most of its activists, and certainly its leader, believe this is primarily a religious and not a political problem. Under this definition the search for compromise is not just futile but dangerous.
The "No" voters will not all be Paisleyites. Some are indeed just bigots who dislike not only Adams, not only Hume, but Catholics and Catholicism in general. Others live in a world of intense mistrust - of Catholics and nationalists, of British governments, of any Unionist leaders who tell that partnership and co-existence is the way ahead.
One telling feature of the intense debate within Unionism is that the "No" campaign has signally failed to attract the public support of the Protestant intelligentsia. This is not to say that No voters are not intelligent - some of the politicians around Ian Paisley are among Northern Ireland's brightest. But the intellectuals, the senior businessmen, churchmen, academics and so on seem overwhelmingly to be for a "Yes" vote.
The point is, though, that much of the Protestant working class and the small farmers have over the years stuck with Paisley through thick and thin. Every opinion poll suggests his core support is unmoved by all the talk of reconciliation, fresh starts and new horizons.
One of the features of the referendum mechanism is that it requires doubting Protestants actually to go out and vote. Much of the change that has already taken place in Northern Ireland has involved only their passive acceptance, but this time they are being asked to perform an act of positive affirmation for radical reforms. On one reading this is a drawback for the "Yes" campaigners but on another it may prove an asset, since it will increase the sense of personal and communal commitment to the new deal.
But whatever the result, Paisley is not going to go away, you know, for after today's vote it will be straight back into the political trenches for the assembly elections of 25 June. One appalling vista for the authorities has him, in concert with the "No" faction within the Trimble camp, harrying and harassing the weaker links until the whole deal becomes completely bogged down.
But another theory, which is not at all fanciful, sees a decent "Yes" vote, following which many of the Unionist doubters accept that a cross- community majority has spoken, that the movement of those tectonic plates is irresistible and inevitable, and that the agreement should be given a fair wind.
If that is the case then perhaps the sky's the limit. Intense political controversies will go on for years but perhaps the dead weight of all that awful history, all that stifling sectarianism, all that culture of confrontation will gradually begin to lift. A good "Yes" vote could open the floodgates to a new surge of reasonableness.
Some will continue to revel in division but a clear majority in the populace as a whole is simply fed up with the whole thing, wants it over and wants to stop fighting and get down to constructive business. Today they will speak in the referendum, signifying that they believe in their bones that there can be a better life for all.