Why did Jackson Carlaw resign as leader of the Scottish Tories? Was it because he realised, as he said in his statement, that he wasn’t the right man for the job? Was it because of the multiple knife wounds in his back? Or was it something more fundamental? There’s a political and tactical division emerging among unionists – and nationalists – and it’s helping the SNP to win. Mr Carlaw, I fear, chose the wrong side of the division.

His recent attacks on the SNP and Nicola Sturgeon’s handling of coronavirus demonstrate what I mean. The First Minister, said the Tory leader, was profiteering from SNP-branded masks. She was encouraging supporters to shout obscenities at people crossing the border from England. And she was using her TV briefings to score political points. Mr Carlaw’s tactic, it seemed, was to go in for the attack on every front and go in hard.

But was it the right thing to do? A lot of people do have concerns about the subjects Mr Carlaw raised. The sale of masks decorated with the SNP logo is icky and disturbing, and the scraggly crowd of misfits at the side of the A1 with their saltires and “go home” signs was embarrassing. There will also be lots of people who think that, given the improvement in the coronavirus situation, several hours of government broadcasting every week is no longer appropriate.

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But it’s a question of tone, which is where the tactical division comes in. In recent weeks, there have been calls by activists on both sides, unionist and nationalist, to be more aggressive in putting their side of the story, the argument being that the enemy is getting away with murder and that only coming down hard will work. Ruth Davidson said something along these lines the other day: the mistake unionists made after 2014, she said, was not to put the boot in.

There’s a similar division on the nationalist side. The likes of Joanna Cherry and Angus MacNeil, as well as the dissidents setting up new Yes parties, are frustrated by the fact that Nicola Sturgeon has pretty much stopped mentioning independence and they want a much more urgent approach. And then, of course, there’s Alex Salmond, who’s been wearing out the carpet as he paces up and down waiting for his opportunity.

The division is also starting to show on the unionist side. Kevin Hague, of the pro-union organisation These Islands, said recently that he was depressed by the surge in aggressively belligerent pro-union voices on Twitter and that what the SNP really fears is balance, nuance and informed reason. However, he was criticised by the new anti-nationalist site The Majority. “If Nationalists feared balance, nuance and informed reason,” it said, “they wouldn't be at 54% in the polls.” The Majority says it wants to come down much harder on nationalism and create a new anti-nationalist media.

I get where both sides are coming from. We’re in an unpredictable, politically kinetic situation – stuff is happening quickly and people are changing their minds – and there’s an opportunity, or a need, for unionists and nationalists to develop a strategy that will make the most of the situation (in the case of nationalists) or find a way to stop it happening (in the case of unionists). A change in public opinion, some think, should mean a change in strategy.

But there’s a real dilemma about what to do here, particularly on the unionist side. I’ve spoken to both Kevin Hague and the man behind The Majority, Mark Devlin, in recent weeks and they’re both genuine in their approaches, but it’s not easy to know who’s right. In the past, passion and anger have taken the Yes side a long way and Mr Hague thinks that’s because making an emotional appeal for change is easy; an emotional appeal for unity and common endeavour, he says, is harder. But as far as Yes is concerned, it’s worked, so why change?

But the point is that the passion and anger only took the SNP to a certain point – not long ago, they were stuck at 48-50% – whereas recently they seem to have breached 50% to get to 52-54% and the timing is interesting. Ms Sturgeon has presented her policies on coronavirus very well and support for independence has started edging up just as she has dialed down on the angry rhetoric.

So why is it working for the wider push for independence? I think it could be because of the kind of people who may have been persuaded in recent weeks. The angry types on the Yes and No sides made up their minds a long time ago and aren’t going to switch sides whatever the strategy. But somewhere in the middle is a group of calmer, less partisan Scots who were never likely to be persuaded by fury, jingoism or party rhetoric. They’re much more impressed by the qualities Mr Hague identified – balance, nuance, and informed reason – and those are qualities which the First Minister, on coronavirus at least, has demonstrated in recent weeks.

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Jackson Carlaw, on the other hand, seemed to opt for the other strategy of full-on aggression, but it wasn’t working. Perhaps he listened to the voices who said a more aggressive anti-nationalist attack was the answer. Maybe he thought, like Ruth Davidson now appears to, that he needed to put the boot in.

But the other option is that Mr Carlaw just didn’t think hard enough about the people who remain open to persuasion. They want to see the Scottish Government held to account. They want the SNP to be criticised when it deserves to be (on dodgy branded masks for example). And actually, they also want to see emotion – Kevin Hague says the emotional and economic arguments for the union are inextricably linked – “it’s because of moral solidarity,” he says, “that you have fiscal pooling and sharing” – and I agree with him.

But there’s a difference between holding the government to account at one end and being aggressive and partisan at the other, and I fear Jackson Carlaw just couldn’t find the sweet spot on that political continuum. Nicola Sturgeon, on the other hand, has, for the moment. The question is: will it last? Her calm delivery in a crisis has won more voters to the cause of independence. But any sign of the old, angry ways could just as easily scare them off again.