Oldham West and Royton by-election
Jim McMahon MP (L) shakes hands with Labour Party Leader Jeremy Corbyn after winning the Oldham by-electionGetty Images

Don't let the lack of comprehensive media coverage fool you; the result in the Oldham West and Royton by-election represents a commanding victory for the new Labour Party project – and an unequivocal endorsement for Jeremy Corbyn as its leader.

The party's majority increased in percentage to an all-time high of nearly 63% for the constituency. This is the first time, apparently since Mark Oaten won Winchester in 1997, that a party's vote share has increased in a by-election contested by all the major parties. Turnout, at around 40%, was down from May, which brought Labour's numerical majority down, but turnout at by-elections is always low. There's not a lot of margin for sniping at a result like that, you might have thought.

You wouldn't know this from the coverage on it on 4 December, though, where the spectrum of responses stretches all the way from begrudgingly lukewarm to full race-baiting denialism. The Telegraph is heavily implying electoral fraud, and its front page is currently black with mourning and bewilderment, while a rogue's gallery of other organs have turned a shade of red after their dire prognostications failed utterly to come to pass. The Spectator and the Mail are burying the bad news by talking about how bad Corbyn is at all the other things that aren't winning votes.

It was worse before the by-election. There wasn't a media outlet in the land that wasn't trailing the vote as a referendum on a faltering leadership, and predicting a loss, or at least a skin-of-his-teeth victory, for Corbyn. The knives were sharpened and the wisdom was all prevailing one way: humiliation for the leftist interloper and, with luck, his head on a plate.

So it's very tempting to smile serenely and enjoy the moment, but to do so would be to miss the increasingly pernicious role the media is coming to play in every fresh failed bid to oust a Labour leader.

It is gauche in the extreme to hit out at the Mainstream Media as any kind of organised monolith. As anyone who's ever worked in a newsroom will tell you, it's practically impossible to get people sitting on the same desk to organise themselves. At a certain point, though, with even the BBC, the New Statesman and The Guardian all faux-solemnly auguring Corbyn's Oldham Waterloo, one wonders what he does have to do to get The Media to like him.

There's no Very British Coup-style skulduggery here, just a monocultural upper-middle class that infests the news media at all echelons, and which finds social democracy distasteful to its well-fed and struggle-free existence. So each individual does what they can to paint Corbyn's victories – deals with Saudi, the tax credit u-turn, Oldham – in one light, and goes hard and heavy on his every failure, real or more often imagined.

But here's what I can't work out: did these commentators, who claimed in apparent good faith that "Labour sources" were predicting majorities of 3,000 or 1,000, actually believe what they were saying, or were they orchestrating mischief? Were the majorities really going to be this tiny, or is Guido Fawkes just bad at his job? Did Dan Hodges genuinely think Labour was in dire straits, or was he just doing his Blairite cuckoo jig for the Barclay brothers?

Why did everyone get Oldham so wrong?

It's easy to imagine the Telegraph's editorial board coming together over stiff brandies and deciding to swallow Nigel Farage's ludicrous claims that the Asian community was stuffing the postal ballot. After all, according to them he's now to blame for Britain going to war with terrorist organisations. But how come The Guardian's Rafael Behr was so sure Corbyn was only clinging on? In the end, he "clung on" by 39 points.

The best take is that of Tony Blair-era adviser John McTernan, whose enviable track-record of losing elections around the world makes him perfect for a bitter column in the Telegraph. Up is down in McTernan's world, where he claims the result – which, you'll recall, is by all statistical accounts a big red rip curl in the face of the boo-boys – is both somehow a vindication of Blair and the bare minimum Corbyn should have managed. Frankly, if the unprecedented increase in vote share ends up as a Corbyn bare minimum, we'll end up with that socialist utopia in no time.

I am not a conspiratorial man. I don't think there's a concerted stitch-up in play. I just think we have a stale media that doesn't understand the politics it claims to elucidate, and which is in desperate need of fresh voices who understand Corbyn's gentle brand of social democracy is surging still, and which will get on board before the country leaves them behind.