THIS is what’s going to happen tomorrow. Nicola Sturgeon is going to stand up at Holyrood and tell us how radical her new policy programme is. Ruth Davidson is going to get to her feet and call on the First Minister to rule out a second referendum on independence. And Richard Leonard is going to stand up and say the SNP isn't nearly as progressive as Labour is. Because that’s how Scottish politics is now, despite everything that has happened in the last few days: the same old arguments being fired from the same old trenches.

But has anyone acknowledged what’s really going on here, underneath it all, deep down? As far as I can see – even before we found out about the Alex Salmond claims – there were at least three inevitable political trends starting to undermine the Scottish Government. To be fair, they’re trends that affect pretty much every government after ten years or so (and sometimes earlier) but they create a kind of state of decay that everyone knows is happening but no one acknowledges. At first, everyone keeps walking around like there aren’t cracks under their feet. Then, there are relaunches and rebrands and reshuffles. But the cracks just keep on getting wider.

The Scottish Government is not immune to these effects – how could it be after so long in office? – which is probably why, ahead of tomorrow’s legislative launch, it was so keen to emphasise what it sees as successes. A video was released featuring many soaring shots of many glens and beaches. The press department also released tweets with exclamation marks at the end of them! And the First Minister spoke about what she saw as her finest achievements so far: Scottish growth rising faster than the UK’s, a plan to double free childcare by 2020, and new “progressive” income tax.

However, behind the scenes, those three inexorable trends, those inevitable political factors, are still doing their work, the first being what you might call the happiness factor. This is the difference between what ministers say and what people feel – so in the case of the Scottish Government, it says it is increasing free childcare, but what people feel is that they’re struggling to get nursery provision for their kids. The SNP also says the NHS is doing better than the rest of the UK, but what people feel is that they’re waiting too long for treatment. And so it goes on. A little more honesty about the status quo (and maybe fewer soaring shots of glens) might help, but in the end this happiness factor can really do for a government.

Then there’s the momentum factor, which is perhaps the one Nicola Sturgeon feels most personally, having tried to call a second independence referendum after the Brexit vote. When the momentum is going your way, everything’s hunky-dory, but when the momentum starts going in the other direction there’s pretty much nothing you can do about it. John Major discovered this in 1993, and Tony Blair in 2004, and Gordon Brown in 2010. Momentum also doesn’t always do what it’s told: for example, the Scottish nationalists assumed Brexit would help things go their way but it didn’t. I’m not saying Nicola Sturgeon’s government is anywhere near a critical loss of momentum, but you can see the way it’s spinning. It’s why she attempted a “refresh” last year and is effectively attempting another one tomorrow.

Which takes us to the last, and most dangerous, of all the trends, the impression factor, which is where Alex Salmond comes in. The former first minister denies claims of sexual harassment. There is also not much evidence for the so-called civil war in the SNP. And, who knows, Nicola and Alex may still be great mates. But none of that matters if the impression is of a party that’s divided over unpleasant accusations. Impressions, after all, can be stronger than facts.

But, fortunately for the SNP, there’s a fourth factor that comes into play. In most cases, the first three would be enough to bring down a government – or at least guarantee that it would lose the next election. But this Scottish Government is a special case, in that it’s built explicitly on nationalism, which is stronger and more irrational than mere party loyalty. For many ordinary voters, if a government loses momentum, or is pursuing policies they don’t like, they will switch to another party. But that is not possible for nationalists because the SNP is the only major party that supports independence. Therefore, despite everything, they must stay loyal.

This explains the Alex Salmond crowdfunding fiasco, but it also, ironically, offers hope for Nicola Sturgeon. The reason so many people were willing to pledge money to pay for Mr Salmond’s court case and pledge emotional support such as “I believe you” and “Scotland’s freedom is more important” is because that’s how many nationalists think: Scotland’s freedom is more important than anything, including, it would seem, accusations of sexual harassment.

To that extent, the Scottish nationalist supporters of Mr Salmond are similar to the American nationalist supporters of Donald Trump: whatever the American president does or says, his supporters stay loyal – whenever there is criticism of their man, it also seems to strengthen their belief. Unproven as the allegations against him are, the same applies to Mr Salmond. Just look at the disturbing litany of comments on his crowdfunding page. It’s all a witch-hunt, they say. We have deep and enduring faith in you, they say.

Nicola Sturgeon wouldn’t like to admit it, but that strong nationalist belief – so unpleasantly on show on Alex Salmond’s crowdfunding page – could also work in the First Minister's favour. Many voters will see a loss of momentum in the Government, and they will have an impression of a party that’s divided, but nationalists – even the ones who might think the First Minister hasn’t done enough to support her predecessor – will tolerate all of it (and more) in the name of the cause. Which can mean only one thing in the end: as long as nationalistic feeling remains relatively strong, the SNP can only fall so far. The fourth factor – the faith factor – will protect them.