IT’S election night. It’s 1.45am and Dominic Raab, the Tory candidate for Esher and Walton, has just lost his seat. Two hours later, the SNP’s Ian Blackford is defeated in Ross, Skye and Lochaber. How do I feel about it? Pretty damned good actually. It’s for moments like this that we borrowed the word schadenfreude from the Germans.

Will any of it happen though? Well, don’t discount it because there’s unpredictable stuff going on in this election that means we could get some major upsets. One of those at risk is Mr Raab, the Brexiter who didn’t understand how important Dover is to trade, and the man, too, who said people use foodbanks not because they’re poor but because they have “cash-flow problems”. The under-currents also make Scottish seats like Mr Blackford’s just as hard to predict.

The reason for the unpredictably is a trend in politics that started in earnest in the 1990s but has now reached its apotheosis. In 1997, after a false start in 1992, Labour won the General Election thanks in a large part to tactical voting and it’s been a significant factor in elections ever since. The Tories did well in Scotland in the last General Election, for example, because so many voters chose to vote tactically against the SNP.

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Looking at the polls, this tactical voting trend is going to be even more important this year. According to polling by the Electoral Reform Society, 24 per cent of voters plan to vote tactically to thwart a candidate they don’t like, although it’s amazing the figure isn’t much higher. Theresa May would have won a majority in 2017 if just 0.0016% of voters had acted differently, and this time round, the result will come down to a couple of hundred thousand people. If enough of them vote tactically, Boris Johnson won’t get his majority.

Over the years, it looks like more and more voters have started to understand this and we’re now at the point where tactical voting is almost like a political party of its own. It has led to weird sights such as the former Tory minister Michael Heseltine standing behind a LibDem podium and the former Blair PR man Alastair Campbell saying “don’t vote Labour!” (if Labour doesn’t have a chance of winning). There are also any number of tactical voting websites that will tell you how to achieve your aim.

And it appears to be starting to work. In 2017, Dominic Raab won Esher and Walton with nearly 60 per cent of the vote and if the national polls were replicated in the seat on December 12, he would easily win again. However, the current polling in his seat puts the Tories on 46%, just five per cent ahead of the LibDems. Perhaps Remainers in the constituency who are still wondering whether they should switch should listen to Alastair Campbell: Don’t vote Labour!

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Tactical voting is just as important, albeit more complicated, in Scotland, and there’s evidence that the voters, and the parties, are willing to use it. In recent days – much to the amazement and disgust of some – support for the Conservatives in Scotland has been rising at the same time it’s been falling in England and the explanation has to be that some Unionist voters are choosing the Tories as a tactical vote against the SNP.

There’s also been evidence of tactical thinking elsewhere in Scotland. In Ian Blackford’s seat, for example, there’s been suspicion that some of the candidates are working to an official pact to maximise voting for the LibDems, and the LibDems’ private polling shows it’s having an effect. Some voters may also be unable to resist the chance to take a big SNP scalp in the way they did with Alex Salmond in 2017 (there may be tactical voting against the LibDem leader Jo Swinson in East Dunbartonshire for similar reasons).

What makes the whole thing much more complicated in Scotland is the way that Brexit and independence intersect. For tactical voting to have any serious effect on the SNP, it requires LibDems and some Labour supporters to switch to the Tories, which many of them did in 2017. But will they be willing to do it again this time, now that the Tories are run by hard Brexiters like Boris Johnson? I suspect a lot of Scottish voters would rather die in a ditch.

But the incentive for a big, central group of Scottish voters to behave tactically remains strong. Indeed, the evidence of tactical thinking in Scottish politics underlines a comforting fact about us: there is a still a strong, liberal, progressive, anti-nationalistic centre of voters in Scotland who are just as repulsed by Ian Blackford’s Scottish nationalism as they are by Dominic Raab’s British version.

If the world was different of course, and we were freed of the threats of Brexit and independence (and we had proportional representation), many, if not most, of these sensible centrist Scottish voters would support Labour or the LibDems. Certainly, by any realistic, liberal, progressive test, the LibDem manifesto wins hands down.

However, that’s not the world we’re stuck with, sadly, which leaves many centrist Scottish voters with an ugly dilemma, especially in seats that will be won either by the Tories or the SNP. Many of the tactical voting guides suggest voting SNP to beat Brexit-supporting Tories, but that misunderstands the subcutaneous trends in modern Scottish politics – many Scottish voters do not want Brexit but they do not want independence either. Ideally, they would vote to keep the SNP out of Scottish seats and the Tories out of power at Westminster, but in many constituencies, the system simply does not allow voters to support that option.

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In the end, the result of the election will depend on what this group of voters decides to do in Scotland, and what Remainers decide to do in the rest of the UK, but, with Labour support up in England and the Tories up in Scotland, the trend in the polls would seem to suggest that many are already choosing the tactical option. Nicola Sturgeon’s pronouncement that a vote for the SNP is a vote for a second Scottish referendum, as well as polls suggesting a Tory majority, may also concentrate the minds of potential tactical voters.

And just think of the potential prize on election night if voters do take the tactical option. 1.45am. Dominic Raab is defeated in Esher and Walton. A little while later, Ian Blackford loses Ross, Skye and Lochaber. It may not happen – there’s a good chance it won’t – but the schadenfreude-laden possibility may just be enough for some tactical voters to say: yes, let’s do this!