NOTHING illustrates the hermetically sealed nature of politics here better than reactions to Brexit.
The DUP are the only major party which campaigned for Brexit even though many of its own members didn't want it, but salved their conscience by assuring themselves they would lose the referendum.
As time went on after June 2016 and it became clear how damaging Brexit would be for people here not a single person emerged in the DUP or among supporters to query the party's position.
It's the same on the other side. Not a single person in Sinn Féin, the SDLP or the Alliance party has taken the view that Brexit is a good idea in any respect.
Compare with the Conservative and Labour parties in England - not Scotland which marches to a different tune - where people are at daggers drawn about the way ahead.
Indeed, the wretched Theresa May has spent the past 20 months negotiating with her Cabinet and party rather than with Brussels. Here, not a dissenter.
What is remarkable however is that the CBI here, the majority of large businesses, small businesses, farmers, you name any sector, think Brexit is an enormously damaging prospect but none of them criticises the DUP, much less suggests that the DUP should put pressure on the Conservative party to change tack, something they're in a unique position to do.
Also remarkable is that although leading DUP figures advocate Brexit, the party has no policy on Brexit.
They simply slavishly follow what the Conservative party proposes at any given time without a thought about how it affects people here.
Now that Theresa May has admitted last Friday that "life will be different" - code for economic growth will be slower and people will be poorer - and that we will have "less access to the single market", did anyone in the DUP think to ask what will they do about that?
Has no-one in the DUP the guts or integrity to say that's unacceptable, considering it's the opposite of what May was saying in 2017?
Will everyone in the DUP happily continue to retail Leavers' lies?
As one writer has concluded, May was really accepting that the eejits in the north, in the north-east of England and south Wales who supported Brexit will exist in a parallel economic universe from London and the south-east of England.
OK, it's true they do already. In the north's case, as a consequence of partition - but it's going to get worse.
Will the DUP pay any price for not lifting a finger to mitigate the impact of Brexit on the north? Will they pay a price for continuing to advocate the most damaging form of Brexit buoyed up by the hubris of their temporary position of collaboration with the people orchestrating the damage?
Not a bit of it. Did they suffer last year in any election as a result of supporting Brexit? Far from it. They increased their vote.
What is extraordinary is the effrontery and arrogance of the DUP in pursuing this course of inaction when they neither represent the majority of people in the north nor the majority of people's opinion on Brexit.
Such is the power of the sectarian imperative here that voters go out and vote for a party which is advocating a course of action that is the most damaging to people's prosperity since partition.
Famously, in the American phrase current since Calvin Coolidge's time in 1924, "people vote their pocket book".
Not here. People vote to keep themuns out, no matter how much self-harm it may cause.
Indeed, the more intensely that voting in a particular way annoys themuns adds an extra justificatory frisson to the self-harm suffered.
Thus the DUP take advantage of the temporary sway parliamentary arithmetic affords them to pursue an objective denounced by the majority of the people here and virtually all economic and financial experts as economically disastrous.
No-one in the DUP has been able to cite a single economic advantage for what the party is doing.
There is only a shimmering Shangri-La, a fantasy receding further into the mists with every document the EU produces.
Yet the DUP remain invincible and contemptible in their ignorance.
