These are strange, unsettling times in politics but most especially for Scotland’s party of devolved governance, the SNP.

The resignation of Nicola Sturgeon, the arrest and release of her husband, Peter Murrell, the party’s chief executive. Police searches at their home and at SNP headquarters.

The visceral battle that was the contest to replace Ms Sturgeon.

Plus daily business. Long waits for hospital treatment. Conflict with a newly assertive UK Government over disputed policy items.

And now confirmation, as predicted here last week, that Scotland’s public finances are in trouble, with the prospect of contentious tax rises to follow.

No party could survive that unscathed. Polls – and eager opponents – suggest the SNP is no exception.

Humza Yousaf has two exit routes from potential calamity. He can govern modestly and well, recording progress where he can.

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And there is independence. The unifying cause for nationalists. The reason they are in politics, and in the SNP. The difference.

At Holyrood this week, Labour’s Anas Sarwar constructed a narrative of a “sleaze-ridden government”, run by a “party in chaos”, pursuing a “rotten culture of secrecy” to cover up its failings.

The FM detected “desperation”. But then he turned to the core. Scotland’s problems, he said, arose from UK mishandling, most notably through a hard Brexit, “imposed by a Conservative government” and now backed by Labour.

His solution? Independence.

This line of attack has three advantages for Mr Yousaf.

It allows him to raise the issue of Brexit, disdained as it was by the people of Scotland. It equates Labour with the Tories, arguing they form a UK phalanx inimical to Scotland’s interests.

And it rallies his own anxious troops around the objective of independence. With the added merit of authenticity: he and his party actually believe in ending the Union.

Not sure the Brexit one quite works, at least not yet. Yes, I see the Scottish polls decrying the post-Brexit state of the UK.

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But I would still argue that reflects broader discontent, that there is little zeal accompanying anti-Brexit sentiments. The popular blood is stirred by independence versus the Union – not by plans to enlist in the EU once more.

Reflecting that, Mr Yousaf is now seeking to reinvigorate the independence campaign. The SNP will hold a convention in Dundee towards the end of June to determine the next strategic steps.

It has been suggested to me that Mr Yousaf is more “collaborative” than his predecessor; that Nicola Sturgeon would have arrived in the Caird Hall with a plan ready, one she made earlier.

I am told that Mr Yousaf is ready to listen – partly out of genuine interest and partly to subdue querulous elements by giving them their place.

But there are limits. For one thing, he wants to truncate discussion about process – and move on to the vision of what independence might achieve.

However, he recognises that his anxious party needs to regroup, needs a moment to get back to the fundamentals of independence. Hence he will pose the core indy questions: how and when, followed swiftly by why.

Other points. An Ipsos poll detected signs that independence supporters, Yes voters from 2014, were “beginning to consider voting for parties other than the SNP.”

Not surprisingly, the SNP leader wants to reverse any such trend. He needs to reinstate the SNP as the evident, uncontested avenue to independence.

That is why there will be no interest in the idea of an independence convention, as advanced by Alex Salmond, now the leader of Alba.

For the SNP, that would only serve to spotlight rival parties. One senior SNP figure told me: “There will indeed be an independence convention. In Dundee. In the Caird Hall. Involving members of the SNP.”

Then there is that row over the date of the SNP event, clashing as it does with a march planned by the pro-independence composite group All Under One Banner.

They are less than pleased. SNP leaders have attended such events in the past – and will do so again. But, right now, their focus is upon reviving their own wounded party.

The SNP strategic thinking is that, while marches have a role in making Yes supporters feel good, they do nothing to convince sceptics.

But what of Nicola Sturgeon’s big idea, that the next UK general election should be a “de facto” referendum, should lead to independence negotiations if the SNP demonstrably win in Scotland?

That always had its SNP detractors. But it still has its adherents. A senior MSP told me they would be “horrified” if that option were excluded.

The thinking was that there had to be a clear, sharp link between voting SNP and advancing the cause of independence. I was told: “Fuzzy options are no good.”

Equally, it was suggested to me that fighting a UK election on the basis of what might or might not be extracted from an incoming Labour government was a recipe for voter confusion and SNP failure.

Both Keith Brown, the SNP deputy leader, and Jamie Hepburn, the Independence Minister, have stressed that the “de facto” plan remains extant for Dundee debate.

To the consternation of the SNP’s opponents, part affected, part tactical.

I do not, however, see it surviving the Caird Hall caucus, at least not in the form envisaged by Ms Sturgeon.

Mr Yousaf, I believe, would view it as being too closely linked to the process arguments – the Supreme Court challenge and the rest – which he is seeking to shelve. Also, it belongs clearly to his predecessor, whom he is obliged to disown, for now.

Rather, he glances at the polls which suggest that independence remains relatively popular, even although the SNP vote has declined.

Some would call that a crisis for the SNP. Mr Yousaf, ever the optimist, sees it as an opportunity to realign his party with the concept of independence.

Expect then a new campaign designed to persuade people that independence could bring solutions to those current problems: yes, EU membership but also poverty and the cost of living.

Opponents will seek to label the SNP as the agents of decline. The FM will seek to depict his party as the agents of potential change.