“People,” John Swinney declared, “are crying out for principled leadership.” Was the First Minister of Scotland about to lay into his predecessors? After all, the Scottish National Party has been in government in Edinburgh since 2007, and to describe the leadership record as “mixed” would be polite. Though neither Swinney nor Humza Yousaf has been arrested, so perhaps the party is on an upward trajectory.

But of course he wasn’t. This was the SNP’s manifesto launch. The Bad Leaders were all far away in wicked London. The people of Scotland needed to be free from their shackles, independent, no longer bound by rules set by others, able to choose their own path. As though, say, they were in a well-equipped campervan.

There’s a wonderful certainty to the SNP that sweeps aside all internal contradictions

The general election is always a little odd for the SNP. It isn’t even pretending it might form a national government, so it makes the case instead for the difference that its MPs can make in Westminster. This boils down to being to the left of Labour on every issue, though Swinney put it in grander terms. The other party leaders were “morally lost”, he said. This is not a problem for the SNP, because the party campervan has moral satnav.

The crowd enthusiastically lapped all this up, though the room was smaller than in previous years. Apparently donations to the SNP have dried up. There’s only so much principled leadership people can stand.

As ever, the big topic was independence. “Vote SNP for Scotland to become an independent country,” the manifesto says on the first page. What could be clearer: a vote for the SNP is a vote for independence. And if, as seems likely, plenty of Scots vote for another party? Would that be a vote against independence? Oh you simple child. Of course not.

Swinney explained that the people of Scotland have already had a vote on independence. No, not that one. Readers south of the border may have missed that the SNP declared the 2021 Scottish Parliament elections to be a vote on independence. They didn’t actually win a majority at this election, but “independence-supporting parties” did, which Swinney argued gives him all the mandate he needs to hold another referendum on taking Scotland out of the union.

Pressed on this question, the leader became a little grumpy, which is understandable, because the position is quite clear: if the SNP win, it will be a vote for independence. And if they lose, it won’t matter, because people have already voted for independence, even if, at another point, they definitely didn’t. As Swinney put it: “People in Scotland should have their democratic wishes respected.” And if they got their democratic wishes wrong, that’s fine, because he knows what their democratic wishes really are.

There’s a wonderful certainty to the SNP that sweeps aside all internal contradictions. They have declared a “climate emergency”, but they want to carry on drilling for oil. (Presumably Scottish oil is too nice to cause global warming. That’s the sort of thing that English oil would do.) Their leaders are the most moral leaders, even if a couple of them know a bit too much about the inside of a police interview room. They know that Scotland’s voters want independence even if, the time they were asked, they said they didn’t.

And this, Swinney explained, was vital. “If we get to a point where we just have a casual attitude to respecting democratic outcomes of elections,” he said, “we are in very, very dangerous territory.” Outcomes of referendums, now that’s a quite different matter.