There can be little argument that the Ulster Unionist leader, Mr David Trimble, won a crucial psychological advantage when the referendum result was declared in the King's Hall, Belfast.
Forget the hype and the spin. Set aside - though only for the moment - the raging debate about the exact disposition of the unionist electorate. In the last hour before the declaration it became clear that for both camps the 70 per cent figure had assumed a particular magic.
Mr Ian Paisley Jnr could scarcely conceal his delight when SDLP officials reported the No vote threatening to break the 30 per cent barrier. The No camp didn't quite make it and their disappointment was palpable.
The No campaigners carry a powerful argument about the result, what it tells us about the actual spread of unionist support, and what it might portend for the Assembly election to come. If there is a question mark over their claim to have secured an actual majority of unionist votes, it is at least plain that unionism is split down the middle over the Belfast Agreement. Whatever the media verdict, that fact alone will sustain the DUP, UKUP and dissident Ulster Unionists as they prepare for the second round of this contest. And one could understand the irritation and frustration of Mr Robert McCartney and others confronted by reporters dazzled by the seemingly-compelling evidence of their comprehensive defeat. Yet for all that they declared themselves winners, they had the look of defeat about them.
Certainly in the context of Northern Ireland as a whole, Mr Peter Robinson, of the DUP, offered no dispute. The people - a staggering seven out of 10 of them - had voted for the agreement. And Mr Trimble will enter the Assembly election campaign challenging the very seriousness of Mr Robinson's avowed intent to overturn what the UUP leader will cast as the "settled will" of the people of Northern Ireland.
However, Mr Robinson and his colleagues will not be so easily embarrassed. They will argue, as Mr McCartney did, that it is their fundamental right to enter the Assembly on the basis of their manifesto commitments and to seek to discharge them. And they will be hoping, as some nationalists fear, that the very arrangements designed to ensure parallel consent in the new administration of Northern Ireland will prove the agreement's Achilles heel.
On the basis of the results, it can not be said that the fear is unfounded.
Leading unionist Yes campaigners privately accepted Mr Robinson's prior projection that a 26 per cent No vote would suggest a majority of unionists had voted against the agreement. Mr Robinson swiftly translated the 28.88 achieved into a claimed 56 per cent share of the unionist total. But the picture was and is hugely complicated by the fact that a massive 160,000 people who did not vote in last year's general election did so on Friday. While the battle of the spin doctors roars on, neither Mr Robinson nor anyone else can be clear as to either who these new voters are, or whether, having acquired the habit, they will go back to the polling booths again next month.
The last week of the referendum campaign saw a serious pitch made to attract young voters. Given the momentum for change attracting and sweeping the entire nationalist community, it is likely that some Catholics who don't normally vote did so on Friday. And the clear expectation always was that a section of the Protestant middle class, which had long since stopped voting, whether through apathy or alienation from the unionist leadership, would also do so this time.
THE attendant assumption was that these factors would play to Mr Trimble's advantage and boost the Yes vote. The exit polls, which proved so remarkably accurate, registered nationalists voting Yes at a rate of 99 per cent. And there was no evidence detected in any of the polling of a significant republican abstention. The latter point in particular will be contested by the unionist leadership, and the argument will rumble on. But, in truth we will not be certain of the political landscape in the North until the Assembly election results are declared.
All attention now will focus on the dispositions Mr Trimble makes for that contest. And he must make them very quickly. Tonight in Fermanagh the dissident, Ms Arlene Foster, will seek her party's nomination to enter the fray. Tomorrow Mr Trimble and his party officers meet to consider an application from Mr Jeffrey Donaldson, MP, for a special dispensation to stand in Lagan Valley. Opinion among UUP chiefs is divided as to whether they should or should not permit Mr Donaldson and his troublesome band to contest the election under the party label - or whether, indeed, they have any real option. Mr Trimble's decision - for his it will be - will be seen by some as the first acid test of his confidence that the clear majority of unionist voters are with him.
The Ulster Unionist leader may be tempted by the notion of Mr Donaldson eating humble pie, and the generous welcome he could then afford the repentant prodigal. However, some of those close to Mr Trimble don't think Mr Donaldson remotely repentant. They consider his renewed offer to try to rebuild party unity conditional upon policy stipulations - particularly over decommissioning paramilitary weapons and prisoner releases - which would endanger the agreement itself; and see in the Lagan Valley MP the potential leader of an alternative Assembly party.
Mr Trimble, however, may feel he has to balance this against the impact rejection of Mr Donaldson and his allies might have on UUP supporters who voted No, or Yes but only very reluctantly. And after a weekend of celebrations, nationalist politicians will resume their watchful concern about what the internal management of unionism might yet mean for the implementation of the agreement, in letter and in spirit.