The SNP’s ability to defy political gravity — a poll conducted last month put them on 51 per cent in Holyrood voting intentions — is easier to understand when you consider the alternatives. Jackson Carlaw, unveiled on Friday as Ruth Davidson’s successor at the helm of the Scottish Tories, is a pleasant chap with a certain flair but unlikely to bring the House of Sturgeon to its knees. Scottish Labour is led by Richard Leonard, a man so anonymous there are members of the witness protection programme with better name recognition. Scots go to the polls next May for the Scottish Parliament election and the choice is between the least effective government of the devolution era and an opposition most voters aren’t aware exists.

Nicola Sturgeon’s reshuffle of her government was forced by the departure of finance secretary Derek Mackay, but it has left her front bench stronger than ever. Mackay’s former deputy Kate Forbes, who stepped in and delivered the Holyrood budget on the morning of his resignation, has been appointed his replacement. At 29, she is very young for a cabinet minister — though Claire Sugden was 25 days younger when she was appointed Northern Ireland’s justice minister in 2016 — but even opponents regard her as formidable. Her new deputy, Ben Macpherson, is another rising star, as is Jenny Gilruth, who has been given her first government job as minister for Europe and international development. (These matters are reserved to Westminster but the UK Government shows no interest in enforcing the devolution settlement, so there’s no reason the SNP shouldn’t carry on regardless.)

Last month, I wrote about the SNP reshuffle at Westminster and how it represented a shift to the next generation. The Holyrood reshuffle has done much the same, only this time it also gives the Nationalists a chance to breathe new life into their government and correct course on areas such as health and education where their delivery has been dire. An administration that should be heading for the political scrapheap has been handed yet another chance to renew itself in power.

Today’s news that the SNP’s former Westminster leader Angus Robertson is launching a bid for a Holyrood seat only confirms the worst-kept secret in Scottish politics. His chosen route is through selection for Edinburgh Central, which is currently held by Ruth Davidson, who will be standing down from Holyrood next year. It was something of an upset when Davidson seized this metropolitan, left-leaning constituency in 2016 but the symbolism of a Nationalist regaining it would be potent. It would also set up Robertson as favourite to succeed Sturgeon when she goes.

Forgotten amid all this is the somewhat important point that, after years of promises, Sturgeon still hasn’t delivered a second referendum on independence. She can’t until Westminster allows her to and she’s not minded to sue her way to one or hold a wildcat, Catalonia-style vote. This caution is testing the patience of her grassroots and some of her parliamentary colleagues. Fresh leadership would buy time to formulate a new plan.

And on the other side? Not very much. Downing Street shows only limited interest in the Union and there are Tories who think a second referendum needs to happen, some who have swallowed the SNP’s line about a mandate for Scexit and others who simply think the Union has had its day. That’s the other reason the SNP looks stronger than ever: it is fighting a war in which the other side hasn’t even shown up on the battlefield.