I was thinking about Boris Johnson’s visit to Scotland as I was enjoying a delicious bowl of Baxters Mediterranean Tomato Soup when it occurred to me how predictable – and weird – the reaction to the visit has been, particularly the idea that it hastens independence or is a sign of some profound shift. Quite the opposite. The reaction to Boris Johnson doesn’t reveal how Scotland is changing – it reveals what Scotland has always been like.

What the critics of the PM’s trip are saying is essentially this: Scotland and England are profoundly different/they are on different political paths/etc, Boris Johnson is behaving like a colonial administrator/arrogant English Tory who wants to undermine our democracy/take away our powers/etc, and his visit to Scotland will speed up independence/act as a recruiting sergeant for the cause/etc. There are variants on the argument, but that’s basically what’s being said, including by the First Minister obviously.

But any Scot who’s been around for a while will know none of that is new – much of Scotland has always had a strained and grumpy relationship with Tory PMs, particularly if the Tory PM is a) English, b) posh, c) a woman or d) all three. Scottish politicians have also always used a supposed threat to Scotland as a recruiting strategy and it’s often been successful even when the Tory threat hasn’t been genuine or effective. The only thing that has changed is some of the people doing it, but the result is the same: a Tory PM posing with cans of soup or whatever to “win back” Scotland.

The most obvious parallel is Margaret Thatcher 30 years ago. Just as Mr Johnson visited Baxters last week so Mrs Thatcher visited the Weir Group in Glasgow in the 1980s after a strong performance by Labour and the SNP at the 1987 election. But there was a mismatch and criticism, then as now. Mrs Thatcher was visiting Scotland just before an England v Germany football game and when Lord Weir told her every one of his workers would support Germany, she simply could not believe what she was hearing and debated with colleagues how the Tories could be more successfully “wrapped in tartan”.

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The criticism she received when she then went on to address Scottish issues, or indeed visit Scotland, was pretty much along the same lines as the disapproval aimed at Boris Johnson, except that in the 1980s you could add misogyny to the mix. Interviewed for Charles Moore’s Thatcher biography, Malcolm Rifkind, her Scottish Secretary at the time, said the problem for many Scots was that Mrs Thatcher was a woman, an English woman, and a bossy English woman. Change “woman” to “man “and you can see nothing much has changed.

The response of the opposition parties in Scotland – and even some within the Scottish Conservatives party – is also the same then and now. In the 80s, Labour sold themselves effectively as the patriotic Scottish option that would stand up to the alien individualism of Tory England. Mrs Thatcher also complained in her memoirs that her own Scottish Office used a similar strategy by portraying themselves as standing up for Scotland against her, and to an extent all of it worked.

Thirty years on, not much is different, except for the combatants. Instead of Mrs Thatcher as Evil Out-of-Touch English Tory, we have Mr Johnson as Evil Out-of-Touch English Tory and instead of Labour as the Scottish Defender, the SNP has taken on the job, using the same language and the same patriotic tropes. Interestingly, over the weekend Tony Blair was talking about a Labour revival in Scotland, but how would it happen exactly? Would it try the same Scottish patriotism of the 80s and 90s because it ultimately proved disastrous for Labour and was hijacked by the SNP.

The other issue with the pro-Scottish, anti-English-Tory strategy of first Labour, then the SNP, is that it has always been pretty misleading. In the 80s and 90s, Labour said Scottish values and institutions were under threat from Thatcherism, but now the goodies as well as the baddies have changed and instead of Labour telling us that only it can stop the Tory threat, it’s the SNP saying the same thing about independence being the only option.

However, the threat to Scotland’s identity, policies and institutions was pretty spurious in the 80s and is even more spurious now. Part of the reason Mrs Thatcher was attempting a Tory re-boot in Scotland in the late 80s was because she felt – rightly – that Thatcherism hadn’t taken root in Scotland in the way it had in England. Scottish institutions had enjoyed a strong separate identity for hundreds of years, particularly the law and education, and many of Mrs Thatcher’s reforms, such as competitive tendering for public services and self-government for schools, did not really happen in Scotland because of that separate identity.

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Three decades later, the same factors apply – only more so. The SNP is still talking about a threat to Scottish policies and institutions – privatisation of the NHS, for example, or a “power grab” by Westminster – even though health is devolved and there has never been as much devolution as there is now. What it means is that, as Scottish government and policies have been increasingly devolved and separate, and by extension English Tory PMs have become less of a threat, the SNP has actually shouted louder about the threat.

Why does it do it? Because it worked then and it works now. In the 80s and 90s, Labour entrenched its position in Scotland using the patriotic, anti-English Tory strategy and now the SNP is doing the same and it doesn’t matter that, thanks to devolution, the English Tory threat they use is much, much smaller and insignificant than it was 30 years ago (and even then it wasn’t great). The size of the threat has not adjusted the volume of the screams. Quite the opposite: the smaller the threat, the louder the screams.

And we know Nicola Sturgeon’s take on the situation: she says Boris Johnson visiting Scotland hastens independence, but can we really be sure of that? Tory PMs have always been unpopular in Scotland – still are – and the opposition has always portrayed the PM as an alien when he or she visits – still do. In other words, the PM’s visit to Scotland isn’t a sign of how much has changed. It’s a sign of how much hasn’t really changed at all.