One of the more depressing features of the devolution era has been the willingness and frequency with which the British nationalist parties have sought to undermine the Scottish Parliament.
This has manifested itself in a host of ways - from the Conservatives campaigning against the very existence of devolution to Scottish Labour working to undermine public confidence in the institution by refusing to send its best minds to Holyrood (for Scottish Labour, of course, thinking is a matter reserved to Westminster), and instead filling the chamber with a combination of the comically stupid and the terminally bitter.
In the early days of devolution the Liberals, to be fair, did try and make it work. Albeit with no other real option, they sent the best they had to Holyrood. They developed some progressive and innovative legislation in the short period of Unionist rule within the confines set by their Scottish Labour partners that Scotland must never be tangibly different from Britain.
But even the Liberals have given up on devolution. With Scottish Labour turfed out of office, the Liberals made the awful mistake of appointing Nicol Stephen - a Unionist so hardline and bitter he made Ian Paisley look like a Shinner - as their leader. A hardline and bitter leader led to a hardline and bitter party, which would obstruct the governance of Scotland at every turn. The party has never recovered, and has become more obdurately Unionist over the years, even as they saw their number of constituencies collapse from 16 when the SNP took power, to three, to one.
But recently the Unionists have been ramping up the idea that devolution itself is illegitimate.
In the last parliament, Scottish Labour had for part of it a leader who actively campaigned against devolution. Their erstwhile deputy leader denounced the devolved institutions as "not democratic". Their Conservative partners contain in their ranks today not a few MSPs who would gladly abolish devolution tomorrow if it was possible, and the rest would accept any unilateral British abolition of devolution as a sign of being a Good Unionist.
But it's only in the wake of fundamental disagreement between the Scottish and UK parliaments that the extent to which the Unionists will undermine the devolved institutions. Devolution is the settled will of the Scottish people, expressed in an overwhelming referendum victory 20 years ago, and reaffirmed in the now-discredited referendum of 2014.
That devolution settlement, promised by the British during the 2014 campaign, promised a powerhouse Scottish parliament in a near-Federal UK. However, the British government reneged on their promise to enshrine the Scottish parliament within the constitution within months of getting their No vote.
And now, with Brexit, it's becoming clear that the Unionists are actively trying to delegitimise the Scottish parliament. The cross-party vote in Holyrood for Scotland to stay in the single market was denounced by the Unionists the moment the British regime announced -without consultation - that they were taking Scotland out of the single market.
It's taken 20 years, but we've finally come to the first major constitutional crisis between Westminster and Holyrood. And in that very first constitutional crisis - between the elected Scottish parliament and a Tory prime minister with no mandate from her party, much less the country - the Unionists have leapt to the defence of the Union Jack immediately.
They have abandoned any remaining pretence of supporting a "strong Scottish parliament" in favour of a parliament entirely subordinate to the whims of the British government of the day.
It is a dangerous precedent to set. But it's the one they have: the Scottish parliament is allowed to make decisions and take positions only insamuch as they do not come into conflict with the British government - and, where they do, the will of the British government must always prevail.
I wonder how long it will be before the British government offers them their reward: the noise will soon start that it is democratically unacceptable for a party to govern Scotland for 14 years or more on less than 50% of the vote - and that powersharing between the pro-independence parties and the Unionist parties will be implemented, Stormont-style.