YOUNGER readers may find it difficult to believe, but years ago, before sophisticated polling methods, instant access to online information and the ability of parties to microtarget likely supporters with messages that might influence them, we occasionally had a rough idea who was likely to win an election the day before it.

One reason it’s hard to predict the choice this time is that no one much – apart from the true believers committed to the Nationalists, the Corbynite wing of Labour, or to Brexit – is terribly enthusiastic about what’s on offer. The Tories’ poll lead may be clear, but that’s because of the extraordinary unpopularity of Jeremy Corbyn, recently on an approval rating of -76, rather than enthusiasm for Boris Johnson, whose own rating is well into negative figures.

There has been some argument about whether the polls have narrowed (which seems likely), or whether both Labour and the Tories have simply gained similar levels of new support (from the Lib Dems and Brexit Party respectively). If the latter, it’s the Conservatives who should worry, since they may have run out of voters to acquire, while widespread tactical voting could yet help Labour deny them a majority, even if no one thinks an outright Corbyn win is plausible.

There are several factors in the uncertainty and variation in the polls that can be identified; one is the degree to which they factor in past voting intentions (it’s swing voters in marginals, after all, who determine any election); another is the reliability of those canvassed.

You’ll remember the “youthquake” – it even became word of the year – which turned out for Labour the last time, and led to the party doing better than expected. You may not remember that six months later, the British Election Study team concluded that it had never happened, and that the turnout amongst the youngest voters may even have fallen between 2015 and 2017.

Even more remarkably, polling companies have found that as many as eight per cent of voters are mistaken about who they voted for the last time. With data like that, you may as well be rummaging around in chicken’s entrails. This problem, like all problems, is amplified on social media, the ultimate dunces’ playground.

The very nature of connections on Twitter and Facebook has led swathes of people to believe that they are in tune with the whole country, poised on the brink of a landslide, when in reality it is just people who already share the same opinions.

That may delude the true believers I mentioned above, but one other group – those whose priority is Remain at all costs – have the added difficulty that, while convinced they’re right and in the majority, it’s not certain who ought to get their vote. There are three-way marginals, such as Midlothian, Kensington and Portsmouth South, where (if the aim is to stop the Tories), the other parties are close enough for it to be unclear which should be backed. There are quite a few former Labour seats that went SNP in 2015 and then Tory in 2017.

And, because independence is as much a factor as Brexit, widespread tactical voting is likely to shore up the Conservatives (the opposite of what the party can expect in Remain bits of England). There’s some evidence, though, to suggest that the combination of Brexit and Mr Corbyn’s unpopularity could lead to previously unimaginable gains for the Tories in Labour strongholds in the north of England.

The problem is that there’s no guarantee this strength of feeling will lead to turnout – as it turned out, it didn’t for the youth vote – or that the result in those close seats will turn out as those stop/get Brexit/Independence voters wish. Around 13 per cent of voters haven’t decided who to back – and given the lacklustre state of all the parties, it would seem quite reasonable for them to stay at home, particularly if the weather’s bad. In an unusual December election, that may be a significant factor in itself.

The fact that one poll suggested as many as 40 per cent of the electorate thought it possible that they would change their minds before polling day may account for the way in which all sides have pushed their own agenda, rather than engaging in debate, and the reluctance of all the parties to have their proposals and the real world brought too closely together.

As the screenwriter William Goldman once said of the film industry: “Nobody knows anything.” The last election disabused the Tories of the idea that a poll lead means it’s in the bag. Even Corbyn fanatics must surely realise that their adoration of him is matched by the antipathy of (a great many more) people. The Lib Dems can’t pretend they can gain more than a handful of seats – if people vote tactically. The Nationalists may discover that being the incumbents, and pushing another Indy ref, may cost them more than it gains.

Hence the general air of panic, ignorance and bluster. Even if the parties have polling that suggests good news (for them, obviously, not us), they can’t trust it. Just as we can’t trust them.