It could be close next Thursday: much closer than most polls and pundits have been predicting for the past two years. Far too close for comfort even when, as I still expect, the Better Together campaign carries the day and Scotland remains – just about – within the United Kingdom.
The Better Together campaign has been dreadful. No passion. No focus on the future. Nothing to trample down the "a nation once again" emotion, hope and rhetoric of Alex Salmond.
My own suspicion is that Better Together assumed from the outset that the polls were correct and that they didn't really need to do very much in terms of persuading for the Union, let alone trying to win over either waverers, or "soft" nationalists.
And now that their early lead has shrunk – possibly even been overturned – they have gone into panic mode and are offering almost anything to secure a victory, regardless of how wafer-thin it may be.
The odd thing is that Better Together has made the same sort of mistakes that unionism has made over the years in Northern Ireland: far too much criticism of their opponents and not enough effort to set out the value and merits of their own beliefs.
It wasn't so much a case of "stay in the United Kingdom, because of what we have done together over the centuries" as "if you leave the United Kingdom, you'll be worse off financially and be nothing more than a political minnow".
That's a very negative way to approach this sort of campaign. You need a narrative. You need a vision. You need a light that attracts. This should never have been turned into a battle about the status quo versus a new, sovereign, independent nation, because raw emotion will always have an appeal to voters that the same-old, same-old never can.
Whatever the result – a close Yes or a close No – it will have an enormous impact on unionism here. Either way, it will spook them, because it damages their whole argument about the constitutional and geographical integrity of the United Kingdom.
They also have to deal with the response of republicans who will say one of two things: "Yes, Scotland remains in the United Kingdom, for now and only by a whisker"; or "Scotland has gone, so where's your argument now about a united Kingdom?"
In September 2012, at a dinner celebrating the centenary of the Ulster Covenant, Peter Robinson talked about the need to create a Council for the Union to bring together all of the pro-Union interests, groups, parties and campaign bodies under one umbrella.
It was a sensible idea, a good idea, and a chance for those who believe in the Union to marshal their arguments and present a coherent, attractive, broad-based case for the United Kingdom.
Yet within a few months, the Council for the Union had morphed into the Unionist Forum, an excluding, circling-the-wagons vehicle for unionist/loyalist parties and the Orange Order.
The referendum result, irrespective of the outcome, is going to change the nature and character of the United Kingdom. Increasingly, attention will be paid to the nature of the relationship between the partner countries of the UK as well as to what we actually mean by the term "unionist".
If Scotland does stay, it will become like a constitutional granny flat, with unionism defined as something which separates, yet unites us. It will officially be allowed to become "a place apart".
It will be "in" the United Kingdom, but not "of" the United Kingdom and with every likelihood of another referendum just around the corner.
So what should unionists here do? It has become fashionable for unionist politicians to claim "support for the Union has never been stronger". But where's the hard evidence for that? The electoral gap between unionist and nationalist is diminishing. Alliance is agnostic on the Union. There is no middle-ground, pro-Union party. Catholics do not vote for unionist parties.
There is still an opinion that upwards of 25% of Catholics support the Union; yet not one scrap of evidence to suggest that they are prepared to vote for any unionist or pro-Union party.
So why does it seem to be taken for granted that they would, in a border poll, vote for a cause that would be championed by the very parties for whom they refuse to vote on any other occasion?
It's an important question, because there is evidence in Scotland that a significant number of people who should probably gravitate towards the Better Together camp are being put off by the organisations and parties behind Better Together.
It seems inevitable that there will be a border poll in Northern Ireland fairly soon: yet it seems to me that the pro-Union side is altogether too sanguine.
They need to face the fact that many of them (including me) failed to predict the scale of the electoral rise of Sinn Fein on both sides of the border. They need to face the fact that many potential pro-Union voters would still find it very difficult to support a campaign – even in the privacy of the polling booth – backed by the DUP/UUP/TUV/PUP/Ukip and Orange Order.
They need to face the fact that the Union, unionism and United Kingdom they champion is changing and will continue to change. In other words, they need to get their act together and work out what they, themselves, mean when they talk of the Union and unionism.
Is it about Orangeism, Protestantism and anti-Irish republicanism? Is it about pan-UK unionism, or simply the right to allow Northern Ireland to be a little bit different while propped up with an annual subvention?
Is it about equality of citizenship, or the chance to stop abortion and equal marriage? Or, putting it bluntly, what does it mean to be a unionist in Northern Ireland?
Unionism is a fractious and divisive beast, prone to splintering, squabbling and acting against its own self-interest. The next border poll will be nothing like the 1973 border poll, which was boycotted by nationalists. The next border poll will pit unionism against nationalism in an entirely different way; a way that will force unionism to explain exactly what it is and why it is worth preserving.
And it's worth bearing in mind that it's pretty certain that there'll be no support worth speaking of from Conservatives, Labour or Lib Dems. Unionists here will be on their own: and there's an irony for you.
If Northern Ireland and unionism are to survive, then the pro-Union lobby needs to be ready for the border poll and coherent enough to avoid the catastrophic errors and complacency of Better Together.
Alex Kane is a writer and commentator