Brexit has not only been done but, Northern Ireland apart, has also largely fallen off the media agenda. Yet this does not mean that the political consequences of the decision to leave the EU are all behind us.
Next week’s election in Scotland will be the next chapter in Britain’s Brexit story. For Brexit has had a significant impact both on the level of support for independence and on its character. And that in turn has had an impact on the pattern of support for the political parties, too.
During the campaign before the 2014 referendum, there was a lengthy debate about whether Scotland could be a continuing member of the EU if it became an independent country. The Yes side argued it could, the No campaign took the opposite view.
Yet in the event the debate was a waste of time. There was little relationship between people’s attitudes towards the EU and their attitude towards independence. According to the British Election Study, while 48% of those who two years later went on to vote Remain voted Yes in 2014, so also did 41% of those who backed Leave.
That picture was replicated at the EU referendum. According to the same survey, the 62% of Yes voters who supported Remain were almost exactly matched by the 60% of No supporters who voted that way.
That pattern changed, though, after the EU referendum. By the autumn of 2016 YouGov were finding that those who voted Yes and Leave (65%) were less likely than those who voted Yes and Remain (86%) to say that they would vote Yes again.
However, this movement was being counterbalanced by what was happening among No voters. Those who had backed Remain (74%) were less likely than those who had voted Leave (93%) to say that they would vote No again.
In short, some Yes-Leave voters switched to No while some No-Remain supporters were now backing Yes. As a result, by the second half of 2018, support for Yes among Remain voters was running at 50% in the polls, compared with just 34% among those who had backed Leave.
Yet, at 46%, the average level of support for independence among voters as a whole was little different from the 45% that had been registered in the 2014 referendum.
But given that there are nearly twice as many Remain (62%) as Leave (38%) voters in Scotland, there was clearly a possibility that support for independence would eventually rise.
During 2019 that was what happened. The polls that year recorded an increase in support for independence to 49%. All of that increase occurred among those who had voted Remain.
By the time of the 2019 general election campaign, support for independence was running at 55% among Remain voters, while it had slipped to just 30% among Leave supporters.
Not only had Brexit changed the character of support for independence but its pursuit had now occasioned an increase in support too – leaving Scotland more or less evenly divided between nationalists and unionists.
Support for independence rose further last year – and has since fallen back again to 49%. But the Brexit divide is as sharp as ever. In the last two months, the polls have recorded just 32% support among Leave voters but as much as 54% among Remain supporters.
This change in the character of support for independence has also been reflected in the pattern of support for the parties.
When Scotland last went to the polls to elect its own parliament – in May 2016, seven weeks before the EU referendum – support for the SNP was (according to the British Election Study) almost exactly as high among Leave supporters (44%) as it was among Remain voters (45%).
However, backing for the party among Leave voters fell heavily at the 2017 general election – and has never recovered.
The latest polls put support for the SNP at 55% among Remain voters but at just 29% among Leave supporters.
Meanwhile, support for the Conservatives is now very firmly linked to backing Brexit. The party is running at 44% among Leave voters in the latest polls (up 14 points on 2016), but at just 15 points among Remain supporters (down two).
While winning the support of Leave voters can be an electorally winning strategy in England & Wales – as Boris Johnson demonstrated in 2019 – it only holds out the prospect of securing a niche market north of the border.
When Scotland last went to the polls in 2014, independence versus the union was a one-dimensional question. But thanks to Brexit it – and thus the choice between the parties next Thursday – is not only about Scotland’s relationship with the rest of the UK but also about Scotland’s relationship with the EU too.
For some voters that makes all the difference – and that difference might yet be crucial to the future of the Union too.
By Professor John Curtice, Senior Fellow, UK in a Changing Europe and Professor of Practice, University of Strathclyde.