Is this the election The Sun finally became the one wot lost it? The Rupert Murdoch-owned newspaper has been renowned for its ability to pick an electoral winner, indeed, to create one, for decades. It has been on the right side of every election since Margaret Thatcher came to power in 1979.

Only last year the newspaper’s editor Tony Gallagher crowed about the continuing power of the press after the nation voted for the Brexit his paper had pushed for. “So much for the waning power of the print media,” he told the Guardian's Jane Martinson.

The Daily Mail and the Telegraph have been less consistent at picking the parliamentary victory, because they have been very consistent in backing the Conservatives. They’ve both backed the Tories in every election since the Second World War (except for the Mail’s endorsement of a Lib-Con coalition in 1974 against, shockingly, Harold Wilson’s Labour).

But while those two papers have not been on the right side of history when a candidate from the left of politics enters Number 10, there has been little doubt about their power to harm the chances of any politician they turned their sights on.

And, along with The Sun and The Daily Express, they certainly turned their sights on Jeremy Corbyn. The right-wing press, now accounting for the vast majority of UK newspapers in terms of number of titles and sales of print copies, carried out a sustained and vicious monstering of the Labour Party and its leader, before and during the campaign.

“It rivalled the attacks on Kinnock, Scargill, Foot, and Benn, and was probably greater than all [of them],” says former Mirror editor, City university lecturer and Guardian commentator Roy Greenslade.

By rights then, Theresa May should have had the cake walk many were predicting at the start of this election. But instead, her slim majority has been eliminated while Labour made stunning gains. Corbyn may not have won a majority or overtaken the Conservatives in seats, but the electorate jumped in the opposite direction from the one the right-wing press were urging them to.

“Spending basically two weeks demonising a man, a leader, and still they don’t pull off a victory for their chosen one, suggests they are out of touch, out of touch with the electorate as a whole, though not necessarily their readers,” says Greenslade. “It’s the end of the hegemony of news print from the right.”

There are a number of factors at play in the declining political influence of the UK’s newspapers, and while Corbyn was ideally suited to take advantage of them, it is mostly down to long-term trends.

Most obviously, they are simply selling fewer newspapers. Print newspaper circulation has been on a downward trajectory for decades. The Sun and The Mail, the UK’s two best-selling daily newspapers, barely break 3m copies sold. They claim many more actual readers, but we are long past the point when print newspaper reading of any kind was a regular occurence for the majority of the population.

And then there’s the fact that the audience they do have in print tend to be older. More than half The Mail’s readers are over 65, as is more than 60 per cent of The Telegraph’s. Even The Sun’s readers are on the older side, with more than 27 per cent over 65 and a further 34 per cent over 45. If Corbyn's campaign really does turn out to have been built on increased youth vote, it will underscore the limits of newspapers with a shrinking audience of older readers.

Of course all these newspapers have digital operations - in the case of The Daily Mail's online sister title Mail Online, the largest English language news site in the world. But being part of a digital news consumer's varied diet of articles is very different to being a print reader's main, or sometimes only, source of information. And in search of digital readers, most right-wing newspapers have moved into more frivolous subject matter. It's entirely possible for a regular reader of The Mail's sidebar of shame to never see one of its Corbyn bashing front pages.

There is also evidence that the right-wing politics of the UK's newspapers simply doesn't travel well on social media. BuzzFeed News carried out a (much copied) project tracking news across social media which found that during the campaign pro-Conservative News stories were barely shared, even by right-wing readers. In fact, almost all the stories about politics that were were being shared online were pro-Labour.

This is unlikely to be purely a function of age. Left-wing messages – increasing funding for nurses, pursuing peace and tolerance – are more easily presented in positive terms than the right’s insistence on hard choices, austerity and security. If the "shy Tory" effect stops people telling pollsters they are planning to vote Conservative, imagine what it does when people are deciding what to share with their online network of firends and family?

Add to that the emergence of hyperpartisan, social media savvy left-wing sites – almost all active cheerleaders for Corbyn – and the right-wing press are fighting a losing battle online, at least when it comes to politcial messaging.

As BuzzFeed’s political editor Jim Waterson put it on Twitter: “I think the Conservatives are going to have a serious media problem as audiences shift online. Currently cushioned by newspapers.”

Following this election, it looks like that problem has already come home to roost, and the cushion provided by newspapers is looking pretty threadbare.

It’s of course possible to overstate the declining political influence of print newspapers on the UK’s politics. Theresa May will surely be hurt, both personally and politically, by the headlines following her party’s embarrassing loss of seats.

Charlie Beckett, director of London School of Economics media thinktank Polis, says the furore over the Tories' "dementia tax", a story run by both left and right-wing newspapers that hurt May, shows the press still have cut through. Yet he also sees the online reaction to the front pages put out by the right-wing titles undermining their impact.

"Social media means that whenever The Sun or Mail comes out with something, there's thousands of people coming out saying 'oh go away'," he says. "People can see other people being much more sceptical. It’s now cool to say 'get lost' to the mainstream press. I think generally people are much less vulnerable to that manipulation."

Whatever the combination of causes, Corbyn’s success in the face of such vehement opposition from the media barons who have so successfully shaped UK politics – the Barclay Brothers, the Murdochs, the whirlwind of obscenity that is Mail editor Paul Dacre – seems hugely significant.

"It's a tipping point," says Greenslade. "No one will be able to take for granted their power again. It has leaked away, this election shows it at its lowest ebb."

It's a low watermark the right-wing press, and perhaps even the Tories, may find it very difficult to recover from.