If the most significant decision taken yesterday was on the Belfast Agreement and in Northern Ireland, the most gripping struggle has been for the votes of unionists.
In one of the last but liveliest encounters of the campaign, on UTV, David Ervine explained what he believed to be the heart of the matter.
This, he said, was a contest between new unionism and old unionism. New unionism, he implied, was capable of managing the change which was coming more rapidly than the people of Northern Ireland imagined. Old unionism, which couldn't, or wouldn't, budge, would be overwhelmed by it.
Sammy Wilson of the DUP disagreed - true to his Paisleyite principles, fundamentally. For him, it was not a question of right and left, or change and how to manage it, but of right and wrong.
What's more, it was clear that he believed beyond shadow of doubt that he was right. Of course, to people of any persuasion who approach an issue believing that they alone have the right air of it, change is out of the question.
Where a course has been ordained by heaven or history, God and the Bible or the dead generations, there's no room for doubt; and believing you have a choice is heresy.
Ask your local bishop, who's likely to have been episcopating against the wind for years, arguing against sex education here and integrated education there; laying down the law where he can get away with it, compromising where he can't.
Certainty is a terrible thing, almost as implacable as its near neighbour, inevitability, as described by Malachi O'Doherty in a sharp and thoughtful book, The Trouble With Guns, and practised by fundamentalists, political and religious. O'Doherty's subject is the IRA; and the form of inevitability, it is something called automacity. Like me, you've probably never heard of it, though it's a ploy familiar to all of us.
As O'Doherty writes: "Auto macity is the principle that your forces cannot be controlled or bartered with." This makes them much more dangerous: a human force "is made as unthinking as a landmine". Its violence has the inevitability of the workings of a machine.
In the case of the IRA, "violence was presented as an inevitable product of political circumstances, which could not be curtailed or reasoned with". Whatever happened, history, Britain or the unionists were to blame. Just as, on the other side, IRA activities were used as an excuse for refusing to recognise the grievances of Catholics or to reach an accommodation with their constitutional representatives, the SDLP.
The decisions taken yesterday by the people of Northern Ireland and the Republic rob the self-appointed consciences of political and religious fundamentalism of some wellworn excuses. No appeal to history or heaven, the Bible or the dead generations, can take precedent over the wishes of the people, clearly expressed after a full and open debate. Not in 1918 but in 1998.
What matters is that emphatic majorities, North and South, have endorsed the agreement. No one using violence to promote political objectives can now claim to act on behalf of the people, North or South. Nor can anyone claim that it's right or necessary to advance either identity, or support the interests of either community, at the expense of the other: the electorates have chosen to give a chance to a system which fully embraces both.
The agreement made by the British and Irish governments and the leaders of most Northern parties has been endorsed by the vast majority of people on this island. It offers the people of Northern Ireland a platform for the evolutionary development of a society which no longer needs to put lives at risk or waste time and energy on predictable recitals of constitutional cases.
The agreement was the first phase in the evolution, which would not have begun had the paramilitaries on either side refused it a relatively peaceful breathing space. Yesterday's referendum was the second.
By the time you hear the results - and I write in hope and confidence that they will bear out the findings of the latest polls - campaigning for the third phase, the assembly elections, will have begun.
Some of the agreement's critics complain not only that it allows Mr David Trimble and Mr Gerry Adams to make equal claims for opposite camps but presents the prospect of confused and confusing assembly procedures. But the parties to the agreement have accepted the principle of consent - the Union is safe, unless a majority decides otherwise - and the parties also accept that it's perfectly legitimate to aspire to and campaign for a united Ireland.
Peacefully.
As for complicated procedures, Mark Durkan of the SDLP makes the simple and sustainable point that they're intended to achieve and maintain a balance between the communities. When the job is done, they'll wither away. They are, as he said, biodegradable. The job will have been done when the parties find themselves working together on practical matters - spilling sweat, not blood, as John Hume says - and equality is taken for granted.
We have never in this country given fair play to minorities. If we had, there would have been less bother about Home Rule to begin with; and Northern Ireland would have been at ease with itself long ago.
Not that we in the Republic have anything to be smug about. Minorities of all sizes and descriptions have been set apart here and put down: women, the poor, travellers, immigrants, non-conformists of any sort. . .
An outsider looking at the history of the past 75 years in Ireland might well conclude that one of our guiding principles has been: winner takes all.
Mr Trimble has said that's not how it's going to be in Northern Ireland. His explanation of the complex assembly procedures was close enough to Mr Durkan's: a divided society cannot be run like a local council where a majority of 50 per cent plus one will do.
But a curious argument has been constructed around Mr Trimble's political requirement that a majority of unionists support the agreement.
If they do - and it looks as if they will - he will be seen to command the loyalty of a majority of UUP supporters, which should strengthen his leadership.
Listen for the echoes of an older day when some spoke of "the people of Northern Ireland" and meant only unionists, and we spoke of "the people of the Six Counties" and meant only nationalists.
Listen, too, 4to Robert McCartney, who may repeat a suggestion he made on Questions and Answers - that the principle of consent was not the best guarantee of sovereignty. But was it not enough that the status of Northern Ireland would be determined by a majority of its people and changed only when they supported change? Not for Mr McCartney. That, he said, was brutal democracy.
Today we celebrate democracy and the principle of consent. And a maturity that is in the best sense liberating.