Much has been written recently about Sir Edward Carson, the great unionist leader, who declined the offer to become the first Prime Minister of Northern Ireland in February 1921.
Although a strong unionist, nevertheless he regarded himself as a patriotic Irishman. He was not an Ulsterman, but a Dubliner and throughout his life retained his strong Dublin accent.
He wanted a united Ireland, but an Ireland united under the British Crown. Although he regretted the partition of Ireland and supported the setting-up of a truncated Ulster, he saw it as a necessary compromise to keep as many unionists as possible connected with Britain.
However, in 1921, he declared: "What a fool I was! I was only a puppet and so was Ulster and so was Ireland, in the political game that was to get the Conservative Party into power."
What has changed in 2021? Many's a DUP politician, if they are frank, will be privately regretting the same thing Carson publicly regretted in 1921.
Throughout the Brexit debate, the DUP, in particular, have allowed themselves to be puppets in the Tory civil war over Europe.
The DUP MPs, under Nigel Dodds's leadership at Westminster, supported a hard Brexit and supported the hard-line Brexiteers, in the right-wing European Research Group. They opposed Theresa May's softer approach to Brexit, in three successive Westminster parliamentary votes.
Her approach entailed the whole of the United Kingdom remaining within the European Union's customs union. This approach could have avoided most, if not all, of the problematic trade issues that have arisen over the past month, since the United Kingdom finally left the European Union.
DUP MPs enthusiastically supported Boris Johnson and Michael Gove in their efforts to thwart Theresa May and to drive her out of office as Prime Minister. One can have little sympathy for the DUP, especially their MPs, whenever they now vent their spleen at Boris Johnson, because of his shameless betrayal of them over the Protocol.
Boris Johnson promised them that he would get rid of the backstop, which they hated, but instead he delivered the Protocol and the Irish Sea border.
After initially welcoming Johnson's deal with Europe, they were embarrassed into rejecting it, whenever they realised that this was worse than the backstop that was originally proposed.
You really have to ask yourself how could Nigel Dodds and company be so profoundly lacking in foresight? Were they so intoxicated by the pivotal role they had as kingmakers at Westminster, that they accepted whatever pup the Tories sold them?
Had they no sense of long-term strategic thinking about what was best for the future of unionism and their "precious" Union.
Now they blame everybody else for their self-inflicted plight. Some of them see the whole sorry state they are in as a result of a massive conspiracy involving the EU and Irish nationalism to push towards a united Ireland.
Incredibly, they are still in denial that it was Brexit and their stupid miscalculation in supporting a hard version of Brexit, that brought about the current situation.
Bizarrely, the DUP also arrogantly rejected and opposed the pro-European views of the 56% cross-community majority of people here, that voted to stay in Europe.
While they now flail about, shouting incoherently about the iniquities of the Protocol, as they did years ago about the Anglo-Irish Agreement, they forget that there is an even greater existential threat to the Union, namely the increasing prospect of Scottish independence.
This is no longer an increasing prospect, but one that could be realised within a few months, given the widely predicted victory of the SNP in the Holyrood parliamentary elections on May 6.
If that happens, Boris Johnson will be forced into calling an independence referendum, which could spell the end of the United Kingdom as it now is. This will have an enormous impact on our politics.
Surely, any far-sighted unionist must have taken into consideration the hostile reaction of the Scots to Brexit, as a threat to the Union and thereby readjusted their position. But there was none of this by the DUP, or for that matter by the meandering Ulster Unionists.
The DUP with last week's five-point plan, have abandoned Arlene Foster's flexible approach.
She was previously prepared to deal pragmatically with the Irish sea border. Under pressure from the ominous LucidTalk opinion poll putting the party at 19%, she has become a rejectionist.
The reality is, that their support is being systematically cannibalised over Brexit, from both the right and the left, by the TUV and the Alliance respectively.
Their rejectionist policy against the Irish Sea border will go nowhere. It is as futile as Remainers in Britain demanding the end to Brexit. The DUP might as well bay at the Moon.