RUTH Davidson’s eight years as leader of the Scottish Tories have been a relentless rollercoaster.

Standing for leadership was practically her first act in politics; an unknown MSP strapped in by the party establishment as the chosen one to beat the disruptive Murdo Fraser, whose central policy was to create a new party on the centre-right which would take the Tory whip at Westminster, in a system with similarities to Angela Merkel’s CDU and the Bavarian CSU in Germany.

For the purposes of full disclosure, despite not being a Conservative member, Murdo asked me to help him in that campaign and I gleefully did so. My view then was that centre-right Scottish politics needed a great disruption. My relationship with political parties is not emotional; rather it is entirely transactional. They are a means to an end; a vehicle to construct a government. When that vehicle is sitting in a ditch, written off, the sensible thing to do is to get a hold of a new vehicle rather than trying to jump into the wreckage and make it go.

Eight years have passed, and I have three core reflections. The first is that Ruth Davidson has been a very accomplished and successful leader of the Scottish Conservative and Unionist Party, but should would have been an iconic, generationally memorable leader of the party that her opponent wanted to create. Let us remember that Ruth Davidson consistently beats Nicola Sturgeon in head-to-head approval ratings, but her party, a ball and chain to her, can only muster a little over half of the SNP’s percentage.

My second reflection is that, with my hands held up, I now realise that our proposal would not have worked. It was as radical as we thought the members could handle, but with hindsight, not enough.

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A party explicitly formed to take the whip of the Tories at Westminster would have been easily caricatured as Tories in all but name, and perhaps with some justification. Rather than a CDU/CSU type of model, what I would now propose is a Canadian model, whereby the Conservative party stands in Scotland at Westminster, but a new, separate, unconnected and unrelated party stands at Holyrood. As well as creating the conditions for a governing party at Holyrood, it would assuage those Tories at Westminster who felt that taking the Tories out of Scotland entirely is ‘un-unionist’.

My final reflection is that, although I thought at the time that this was a problem confined to the Conservative party, I now realise it is not. The SNP’s success over the last 12 years has been predicated on exploiting the 3 v 1 mentality; we’re Scotland’s party, and they’re London’s parties in Scotland. The Scottish Tories are buffeted by the winds of Westminster, for sure, but they are not alone.

The Lib Dems’ woes following the coalition years were felt in 2015 at Westminster, but also 2011 and 2016 at Holyrood. Labour’s calamitous uncertainty over Brexit, and its anti-Semitism crisis, are savaging its polling numbers in Scotland; it came 5th with less than 10 per cent of the vote in the European Parliament elections. The Canadian model is one which all parties should observe and act upon.

Since 2011 the concept of a separate Scottish party has come and gone. If we charted its progress, it would be very obvious to see that its stock increases in times where the Tory party at Westminster is in trouble, and decreases at times when the mothership is doing well. In the immediate aftermath of Davidson’s victory, the idea went back into its box.

The independence referendum came at a perfect time, as it gave Davidson something to hold on to. She did so with efficiency and vigour, becoming the head of unionism in Scotland and, critically, keeping the issue firmly on the table during the 2016 Scottish Parliament elections and the 2017 Westminster General Election (it is no accident that Ruth Davidson talks about a second independence referendum at least as much as Nicola Sturgeon does).

But as sure as night follows day, when you run downwind at times of relative calm at Westminster, you are going to have to turn around and run with it in your face. Brexit has produced a stiff headwind for the Scottish Tories, and the inability of the Westminster government to deliver it has cost the Scottish party at least five points, so far, in the polls.

Enter Boris Johnson, and now it is blowing a gale. The Scottish Tories saw this coming. Last year, they ran a clandestine campaign codenamed Operation Arse, aimed at persuading MPs to prevent Boris Johnson becoming Prime Minister. The driver was the party’s internal polling; it showed Johnson to be unpopular across all Tory voters – the core, 2016 switchers and 2017 switchers. He was the least popular of all known leadership candidates at that time. His favourability was -40 at a time when Theresa May’s was still +40, and Davidson’s +80.

Operation Arse has failed. And, to make matters worse, Davidson’s ally David Mundell has been sacked, leaving her spitting tacks. So, what now? I suspect that Davidson will do and say very little publicly between now and late-August. She will then re-convene her MSPs and that will be, to borrow a phrase, do or die.

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Ultimately, this is about 2021. Talk used to be of emerging from that election as the largest party. It is now of winning enough seats to stop an SNP/Green majority and the second independence referendum that will have to follow to avoid a democratic outrage. It may yet be an issue of simply retaining enough MSPs to be relevant.

The question for Ruth Davidson is how to maximise her vote in 2021. It is likely to have only one answer. Boris Johnson is exactly the sort of Tory Nicola Sturgeon wants in Downing Street - a posh, rich, southern Tory who led the Leave campaign and has a streak of English nationalism running through him.

But there’s something Nicola Sturgeon doesn’t want. Decentralisation. She doesn’t want Boris Johnson to create a quasi-federal arrangement whereby the Scottish Parliament is offered all the powers that most people (including many Yes voters) want. And she doesn’t want Ruth Davidson to create a new party which can argue from a Scotland first perspective, with no ties to the Tories.

Davidson and Johnson don’t agree on much. But they should agree on this.