Stance on transgender debate was a fatal error by Nicola Sturgeon - Bill Carmichael

And it is a dominance that has been largely unchallenged, despite numerous scandals swirling about the SNP, and a decidedly thin list of legislative achievements.

Through devolution the Scottish Parliament in Holyrood has been given immense power, including tax raising powers in 2017, but this has had little beneficial effect on the Scottish economy or the state of public services.

Indeed, the once celebrated Scottish education system has tumbled down the league tables of international comparisons since the SNP took over, the health service is in permanent crisis, drug abuse deaths have tripled, and the only metrics where Scotland comes top are in alcoholism and obesity.

Add to this scandals, such as the CalMac ferry fiasco where £128m of public money has gone missing, and allegations of fraud over SNP finances, and it amounts to a damning indictment of Sturgeon’s administration.

But throughout it all Sturgeon has sailed serenely on, remaining the most popular politician in Scotland. In the 2019 General Election the SNP won 48 of the 59 seats in Scotland, with a vote share of 45 per cent, blitzing the Conservatives and reducing the once powerful Scottish Labour party to an ineffectual rump.

Sturgeon seemed unstoppable and it seemed only a matter of time before she forced the UK government to concede another referendum on independence, which attracted widespread, although not decisive, support from Scottish voters.

But then she made the fatal error of stepping on the landmine that is toxic identity politics. In a populist bid to appear “progressive”, in contrast to the reactionary English, Sturgeon pushed through a controversial bill designed to make it easier for transgender people to obtain a Gender Recognition Certificate.

Sturgeon personally promoted the mantra that “transwomen are women”. In other words any male born person who identifies as female is indistinguishable from natal born women.

Many feminists, including left wingers and pro-independence supporters, tried to point out that this would have a negative impact on women’s rights, including the provision of single sex spaces in hospital wards, rape crisis centres, women’s sports, changing rooms and women’s prisons.

Sturgeon insisted there should be “no debate” and no dissent, and that anyone who disagreed with the measures were nothing more than bigots, transphobes and racists.

Eventually, the UK government stepped in and blocked the Bill passed in the Holyrood parliament from receiving the Royal Assent, arguing that it conflicted with protections for women enshrined in the Equality Act.

Some pundits saw this as a masterstroke by Sturgeon, arguing she had deliberately engineered this row to inflame tensions and make Scottish voters furious about the interference by Westminster politicians.

If true, she badly miscalculated and the whole thing backfired terribly. The problem with insisting on “no debate” is that legislation isn’t properly stress tested to ensure it is workable. In the event, Sturgeon’s entire gender policy completely collapsed like a house of cards on the first encounter with reality.

The catalyst came with the case of Adam Graham, a shaven headed thug with a face tattoo, who decided to transition to a woman, named Isla Bryson, after being convicted of two rapes.

According to Sturgeon’s ideology, followed faithfully by the Scottish Prison Service, Bryson’s claim to be a woman must be accepted without question, and he was sent to a women’s prison. After all, if “transwomen are women” there could not possibly be any objection to Bryson being housed in the female estate.

But quickly the absurdity of sending a violent male offender to be housed with vulnerable women was made painfully apparent, and amid a huge backlash the decision was reversed. In a series of interviews Sturgeon was reduced to babbling incoherence as she tried to explain that transwomen are definitely women - er, except when they are not.