How do you solve a problem like Jeremy Corbyn?

Many wizened old hands scoffed at the #JezWeCan phenomenon and I confess I was one of those cheerfully scoffing too. Look, we said, however avuncular he may seem, the British people are not going to vote for Jeremy Corbyn. He will lead Labour to 1983, not 1997 and not just in terms of policy either. The result would be a rout; the kind of humiliation that sets a party back by at least a decade.

In like fashion, we recalled that the single most important truth about non-voters is that they do not vote. Appealing to them, then, was a quixotic enterprise, doomed to ultimate disappointment. This was not baseless commentary; we had science – or, at any rate, political science – on our side.

The 2017 election refuted the long-established observation that campaigns usually make little difference

Sometimes, however, circumstances change. There are always exceptions to general rules. The 2017 election refuted the long-established, and deservedly popular, observation that campaigns usually make little difference. Well, this time they did. Late-deciding voters swung heavily behind Labour rather than, as is more often the case, behind the incumbent party.

Meanwhile, the proportion of younger votes who bothered to vote increased by more than 15 points, compared to 2015. Just 30 per cent of “Generation Rent” voters endorsed the Conservatives. Less noticed, but equally importantly, the percentage of pensioners who voted actually fell. Both phenomena helped Labour at the expense of the Conservatives.

• The rise of the young political activists

And so even though – and it is important to insist upon this – Labour did not win the election, Corbyn emerged from it with his reputation enhanced and, just as significantly, with a vice-like grip on the Labour party’s future. The doubters within his own party, to say nothing of his many enemies, must bow to the people’s verdict and kiss the leader’s ring. The right remains baffled and so it has become important to sneer at the young boobies who voted for Corbyn. One day, the thinking (if we can so dignify it) goes, these people will come to their senses and appreciate that Corbyn is not the man they think he is.

Many Labour voters, it is true, seem unaware that Corbyn is a long-time Eurosceptic whose vision for Brexit is considerably “harder” than that of the Labour Party as a whole. But – and this is the crucial point – Corbyn didn’t start it. He didn’t foist Brexit upon a younger generation that, on the whole, voted to remain in the EU. And when he speaks of solidarity and a colour-blind politics in which we should all rub along together he speaks directly to how the millennial mind likes to think of itself: decent and liberal, even if sometimes earnestly so.

The Tories, by contrast, spent so much time courting the Ukip vote they forgot this might be noticed by voters appalled by everything Nigel Farage says and stands for.

• Owen Jones: “Labour’s manifesto genuinely inspired people”

Rallies and music festivals aren’t everything but Corbyn’s comfort in front of a crowd – and his willingness to speak anywhere – is easily contrasted with Theresa May’s evident discomfort whenever she appears in public. Asking the Tory leader to appear at Glastonbury would be an act of cruelty. The Prime Minister’s aversion to public displays of emotion does not make her a wicked or inadequate person, but in the modern era it is undoubtedly a considerable handicap.

The Tories have a London-sized hole at the heart of their electoral strategy and, increasingly, their identity too

John Major wanted a Britain “at ease with itself” and David Cameron was determined that the Tory Party should look a little more like the country it aspired to govern. Some progress was made on that front, only for much of it to be jettisoned, at least as a matter of perception, in the dash to hoover up Ukip votes.

No one expects Tory politicians to be hip or with it or whatever passes for being on trend these days, but a basic ability to understand and speak to the hopes and aspirations of voters under 40 should be considered an entry-level requirement for Mrs May’s successor. That means honouring a social contract which demands that, in return for accepting disagreeable features such as university tuition fees, good jobs and affordable house prices are the reward for studying by the rules.

• Prime Minister Theresa May backs The Big Issue prevention plan

It also requires a Conservative Party that is capable of accepting that the longer-term trends in Britain are metropolitan and multicultural. London is the great maw but also the great driving engine of the British economy and the Tories, if not quite persona non grata in the capital, have a London-sized hole at the heart of their electoral strategy and, increasingly, their identity too.

That can’t be fixed by social media whizzbangs but the first order of business is accepting that the party has a problem. Only then can it move to the secondary matter: doing something about it.

@alexmassie