The unionist parties in Northern Ireland are pulling together. They have looked into the future and have seen a scenario which appalls them.
Parties that support the union with Britain represent the greater part of the Northern Ireland community. The Good Friday Agreement of 1998 ensured that, with the unionist majority in the region, there will always be a unionist First Minister, until demographic change, or mass conversion, alters the inherent balance between the two communities.
That prospect was slightly adjusted by the St Andrews Agreement. The legislation following from that agreement determines that, in the event of the largest party in Northern Ireland coming from the smaller community, that party will be able to appoint the First Minister.
At a time when unionism has been fragmented, the prospect of Sinn Fein being the largest party has appeared better than ever - though they may be nervous of testing the degree to which stories about Gerry Adams's handling of recent abuse complaints have dented their vote.
And Sinn Fein, which no doubt would relish topping the poll, makes the argument that it shouldn't really matter whether the First Minister is a nationalist or a unionist. Their interpretation is that the First and Deputy First Ministers hold equal positions.
For unionists, the difference between the two positions is so important that, apparently, practically every issue which divides the DUP and the Ulster Unionist Party can be compromised to prevent Sinn Fein appointing a First Minister in Northern Ireland.
So, what does this say about unionism?
Well, for a start it says that neither unionist party accepts that the First and Deputy First Ministers are equal. There is only one of those positions which either main unionist party thinks a unionist should fill.
By positioning themselves to form an alliance to prevent Sinn Fein taking the First Ministry, both unionist parties are attempting to refute the Sinn Fein understanding that there is currently a requirement on unionism to treat republicans as equals.
If the unionists are seriously saying that they could not bear to serve under a Sinn Fein First Minister, duly elected, under agreements which they have assented to, then there are disturbing implications that follow from that.
The first of these is that unionist assent to the Good Friday Agreement and the St Andrews Agreement are qualified; they are conditional on the maintenance of a unionist majority.
And that means that unionists concede less to republicans than republicans concede to unionists. And worse, unionists think it right that they should withhold the fullest commitment to the spirit and letter of the agreement which was supposed to have settled conflict here. Republicans are giving unionists something that, it appears, unionists are averse to giving republicans - their compliance with the electorate's wish that they should serve in the Deputy First Minister's position.
Of course, no unionists have said blatantly that they would refuse to serve alongside Sinn Fein in an office which they would regard as subservient.
None have even said that they do regard the Deputy First Minister's office as subservient to the First Minister's - a statement which would be controversial in itself and would cause unease within Sinn Fein.
But their determination to prevent the emergence of a Sinn Fein First Minister, through unionist parties pulling together, suggests that these principles are fundamental to unionist thinking.
How can it be, nationalists wonder, that two unionist parties which have spent most of last 40 years in intense rivalry with each other, would prefer to sink their differences and pursue communal consolidation than to accept a republican as First Minister. Nationalists, after all, regard the supremacy of the First Minister over the Deputy First Minister as merely symbolic.
A Sinn Fein First Minister would not bring us any closer to a united Ireland. But if the prospect of a Sinn Fein First Minister is brought closer by unionist division, then you have to ask why unionists at St Andrews agreed to a clause which permitted the largest party - even a party from a minority community - to take that office.
Peter Robinson was at St Andrews, so was Ian Paisley. Did they like that clause? Was there something in it which served their interests? When a new Assembly meets for the first time after an election, the parties designate themselves as either nationalist or unionist. But it is not the largest designation which takes the First Ministry, but the largest party.The clause which determines that provides a dynamic incentive for parties within the designation to pull together and try to consolidate.
In a place like Northern Ireland, where virtually all unionists are Protestant and virtually all nationalists are Catholic, this amounts to an instrument within the constitutional arrangements for the enhancement and perpetuation of sectarian division.
One of the early critiques of the Good Friday Agreement was that it institutionalised sectarian division, but this clause energises that division, provides the mechanism by which it will grow and deepen.
Yet most of us, when we voted for the agreement, did so in the hope that it would end sectarianism. Unionists would better serve the wider community's hopes of ending sectarianism if they were as willing to deputise for Sinn Fein as Sinn Fein is to deputise for them, when that is the way the votes fall.