The contribution by the main Stormont parties to the Westminster election campaign to date has provided compelling evidence to support the belief that the main threat to the union comes from unionists.
Nationalist politicians on both sides of the border have spent just over a century pushing for an end to partition, but their efforts so far have resulted in only limited degrees of progress, while unionists, by contrast, have managed to deliver a spectacular range of wounds to their own cause in recent years, and are giving the firm impression that they are far from finished yet.
Although it will be accepted that both sides have been responsible for serious errors of judgment in sectors including community relations, it is the way in which unionists have consistently acted against what will be widely regarded as their own best interests which has been striking.
Less than a decade ago, there was a definite sense that our devolved structures, with all their imperfections, were providing a reasonably settled form of government which may not have been delivering strong advances, but, as is always an achievement in our circumstances, were not unduly annoying any section of a divided society.
While the debate on Irish unity had never faded away, many nationalists concluded that their short-term priorities would lie elsewhere as long as a relatively meaningless border remained only technically in place within the reassuring context of the European Union.
A little further generosity of spirit towards nationalism from the DUP group, which at that stage enjoyed a solid Assembly majority, would have copper-fastened its strong position to an even greater degree but instead, as has been well documented, the decision by the party to so enthusiastically back the disastrous Brexit project in 2016 is likely to go down as one of the biggest strategic blunders in the annals of unionism.
It placed the whole issue of borders, first on land and then at sea, right at the top of the political agenda, galvanised nationalist thinking and eventually made the staging of a unity referendum an achievable aim for effectively the first time since the notably vague guidelines for the measure were included in the 1998 Good Friday Referendum.
Some DUP figures also felt unable to resist taking a remarkably aggressive approach to an unthreatening Irish language lobby, and, by the time the full extent of the Renewable Heat Incentive scandal emerged in 2017, the executive was heading for the rocks.
Devolution has since been restored, then suspended again and is now back in place, but along the way the unionist majority at Parliament Buildings has disappeared, probably permanently.
The forthcoming general election was always going to provide us with some further sharp insights, and the bitter splits within unionism have opened the real prospect that two seats of crucial importance to the DUP, East Belfast and Lagan Valley, could be lost to the party.
Both constituencies were already expected to be tightly balanced, and the move by Jim Allister’s Traditional Unionist Voice to specifically target the DUP candidates there has dramatically increased the possibility of gains for Alliance, which is famously agnostic on the union.
The TUV’s intervention is directly linked to the fall-out from the protocol and the Windsor Framework, which were both inevitable consequences of Brexit, even though opinion polls have consistently indicated that most ordinary voters are less than fascinated by the dispute.
It is possible that the DUP could hang on in its two key battlegrounds, but the party is acutely aware that defeat in marginal East Belfast would embarrassingly leave Gavin Robinson as an unelected leader only a matter of weeks after he was finally confirmed in the post.
Such an outcome would also in all likelihood mean that Belfast has no unionist MP for the first time in the parliamentary history of the city, a development of major symbolic and practical significance, and considerable changes have already taken place elsewhere.
Just before I first became eligible to vote in the late 1970s, I found myself having a brief and amicable conversation with my then MP in South Down, Enoch Powell, at a time when he was among the members of the anti-power-sharing United Ulster Unionist Council who held 10 of the 12 Northern Ireland seats in the House of Commons.
Mr Powell, named as a political hero by Nigel Farage - who once paid a memorable visit to the offices of The Irish News which could provide us with a column for another day - was regarded as too extreme for the British Conservative Party of the era, but was able to switch to South Down and be repeatedly elected with the minimum of fuss.
Only eight of the present 18 seats are in unionist hands, and that figure could drop to six if the DUP has a bad day on July 4. It is fair to say that South Down is one of a number of constituencies which will never again return a unionist MP, and would not under any circumstances entertain the arrival of a figure like Mr Powell or indeed Mr Farage.
The tide is flowing in a clear direction, as part of a process which is influenced by demographic and other trends but also indisputably by self-inflicted blows within unionism.
