IT all began with “a line in the sand”. Launching her leadership campaign in Edinburgh in 2011, a 32-year-old Ruth Davidson made clear to her Scottish Tory colleagues that enough was enough. There was to be no more discussion about devolution, no further powers for Holyrood. Fin, finito, end of story. And in retrospect, the image which launched her political career was well-chosen. Shifting sands have become Ruth Davidson’s master metaphor.

In the Spectator this week, Alex Massie suggests the Scottish Tory leader is “interested in ideas,” and experience backs up that assessment. So open-minded is the Scottish Tory leader, that political ideas seem to fall in and out of her head at an incredible rate.

I have, for some time, been trying to pin down what – if anything – Ruth Davidson really believes in. Her support for gay rights is beyond question. I used to quip that her only other substantive commitments were to the Union and lower taxes for the top 10% of earners. But this week, even this observation looks too definitive.

In a speech at the University of Glasgow on Tuesday, Davidson wagged a finger at her Westminster colleagues. Given half the chance, she said, she’d prioritise NHS investments over further tax cuts for the richest. I’ll give you a moment to rescue your jaw from off the floor.

Yes, this is the same Ruth Davidson whose party saw red in 2016 when Nicola Sturgeon’s administration didn’t follow George Osborne in cutting the taxes of the wealthiest Scots. Yes, the same Ruth Davidson whose finance spokesmen characterised Holyrood’s most recent tax-raising budget as “punishing hard work and aspiration”.

It is so astonishingly incoherent – so wandering and mutable – that the hypocrisy of it punches you in the epiglottis, reaches down your throat, and pops your lungs. But the Tory leader doesn’t seem to shed a bead of sweat in executing these death-defying moves. She doesn’t even think to blush.

She’s come a long way. Her first speech to the Tory party conference in 2012 was a pancreas-bursting partisan screed in the 1980s “culture of dependency” mode. Declaring that “only 12% are responsible for generating Scotland’s wealth”, Davidson characterised the nation as a “gangmaster state” governed by a “rotten system of patronage” where the public sector “is the only provider people can see for their housing, education and employment”.

“Scotland could end up making North Korea look like a beacon of free enterprise,” she argued, characterising the abolition of prescription charges and tuition fees as “frittering away tax-payers’ hard-earned cash on throwing electoral bribes at people who didn’t ask for them”.

Naturally, the delegates from the Jurassic, Triassic and Cretaceous periods loved it, but this isn’t exactly the patter you associate with cosy “centrist” Toryism.

But therein lies the great political virtue of Ruth Davidson: she is large; she contains multitudes. If the Iron Lady costume does the trick, she suits up. If not, she dips into the hamper for another rig.

Take devolution. This week she told one UK newspaper, without irony, that “as someone who operates in a devolved administration I know how angry I would be if the House of Commons legislated on a domestic Scottish issue over the head of Holyrood". She must be birling at the EU Withdrawal Bill.

Take immigration. In this week’s University of Glasgow speech, the Tory leader sombrely intoned that “we have, in this country, allowed immigration to be a concept that worries us. Some sort of problem to be fixed,” she says, before suggesting this approach should be “challenged”.

First, let me re-cast that paragraph for you, Ruth. You seem to have left out a few essential facts. Instead, try: “We have – in my party, and throughout my tenure in office – consistently encouraged people to be worried about immigration, and urged them to vote for us as the only people who can fix the problem.”

Perhaps conscious that her shiny new position sits awkwardly alongside the electoral platforms she has consistently endorsed, Davidson instinctively goes into a Biellman spin. “Setting an immigration target reduced to the tens of thousands is one thing when unemployment is running over 8%,” she argues, but “refusing to review it when the country nears full employment and sectors are reporting skills shortages is quite another.” Cantilever, axel jump, and in a bound, Davidson is free.

But hold up. Mark the political footwork carefully. What do you reckon was the rate of UK unemployment when Ruth Davidson launched the Scottish Tory platform of reducing immigration to “tens of thousands” in May 2015? According to the Office for National Statistics, it was 5.5%.

And less than a year ago, in June 2017, when she launched her party’s manifesto which argued “immigration to Britain is still too high” and pledged “to reduce immigration” to “the tens of thousands?” Yes, you’ve guessed it: the unemployment rate was 4.4%. According to the ONS numbers, UK unemployment hasn’t hit 8% for more than half a decade. So why the sudden change of mind now?

In fairness to the Scottish Tory leader, she has often talked a better game than many of the bloodless ghouls in her party. In 2016, she urged her colleagues not to forget “that behind discussions of numbers and rules and criteria, there lie people and homes and families”. She’s right. We shouldn’t. Consider the circumstances of Giorgi Kakava, the 10-year-old orphan from Glasgow Theresa May’s government is currently attempting to return to Tbilisi. Take the case of 21-year-old Denzel Darku, raised at FMQs yesterday, which left the Tory benches looking like a row of frozen gargoyles, grey and unmoved.

I don’t know about you, but I’d prefer a dry-eyed monster in the Home Office who kicks you out of the country without compunction to someone who sprinkles your deportation order with crocodile tears. Brutal it may be, but the stony-faced bureaucrat at least spares you the empty masquerade.

People change. Their views mature. They learn from experience. I get all of that. But since she first impinged on public consciousness in 2011, the solitary constant in Davidson’s career has been its inconstancy. Her political polymorphism seems to have no limit.

One commentator described her as the “most naturally talented politician” in the UK. If a talent for politics means being a practised charlatan with few real ideological commitments and no shame in veering all over the political map – give her the gong. This week, she’s more than earned it.