Remember the curious affair of the blue and black dress? Or perhaps it was gold and white to you. For a few days last year the photograph of the dress that looked one colour to some and different to others was all people could talk about. Blue dress people wondered what the hell was wrong with gold dress people – who were in turn bemused that blue dress people just couldn’t see it.

As a young Labour voter passionate about Corbyn, please don't patronise me Read more

Almost a year on from the first stirrings of Corbynmania, that’s pretty much where Labour is now. Some will see in this week’s Vice documentary on Jeremy Corbyn a sweet man battling against fearsome odds, saying things they’ve waited a lifetime to hear from Labour. Others will see only amateurishness, and the same old rambling speeches he’s been making forever. One sees gold. Things couldn’t be bluer for another. And no, this isn’t a piece about who’s right. It’s an attempt to understand how reasonable people can look at the same dress and see utterly different things.

What’s refreshing about the Vice documentary is that it did what mainstream media doesn’t do enough and took Corbyn seriously as an object of study, a phenomenon to be unravelled. It was a reminder of how rarely we see the view from inside the camp, as opposed to the view from external critics or distant groupies.

The very idea of seeking to understand Corbyn’s victory is a slightly loaded one, given that many Corbynites barely think it needs explaining. As far as they’re concerned, the right man won, and the only mystery is that some people still don’t get it – something too conveniently blamed on media bias against him.

I won’t dwell on the ugly way Corbyn’s supporters booed the BBC’s Laura Kuenssberg on Thursday just for asking a question, or on Corbyn’s unpleasant personal attack on Jonathan Freedland over his excellent recent column on antisemitism.

Journalists haven’t accounted for our failure to see Corbyn coming or understand the devotion he inspires

But even the Vice reporter, a self-professed Corbyn voter, got short shrift the minute he started asking tough questions. The impression is of a man who, having only recently emerged from obscurity, has never experienced the scrutiny senior politicians take for granted – and who resents it.

The idea that a hostile media is responsible for all his woes, however, is fanciful. Sadiq Khan won the London mayoral vote despite the city’s Evening Standard cheerleading for his opponent. David Cameron became Tory leader over the dead body of the Daily Mail. There comes a point where leaders have to start accepting responsibility for their own mistakes, not blaming the papers. But that doesn’t mean we have no questions to answer.

It’s striking that while pollsters who misjudged last May’s general election have openly analysed and debated where they may have gone wrong, journalists haven’t accounted nearly so publicly for our failure to see Corbyn coming or understand the devotion he inspires.

Having been a lobby reporter for 12 years, followed by observing Westminster from a safer distance for the past six, I do think bias is part of the answer. But not the bias you think. Journalists are not out to destroy Corbyn because he threatens to bring down the neoliberal elite, or because they’re all Tories, or because they live in a bubble of groupthink. (The lobby is overly male, pale and Oxbridge-educated, but insofar as I ever knew my lobby colleagues’ private political leanings, they were a much more mixed bag than you’d probably find walking down your street.)

It’s more that most journalists – rightly or wrongly – simply don’t expect Corbyn to win an election. And the lobby has an instinctive bias towards winners – people who either wield power, or might soon.

At its worst, that can mean lazy reporters giving an easy ride to powerful gatekeepers in return for access. But mostly it just means journalists gravitate towards politicians who are likely to have an impact on readers’ everyday lives or who can help them understand what’s happening behind closed doors. People, in short, who make news because they make things happen.

Thus ministers floating even a half-formed idea tend to command the front page, because they could feasibly turn it into reality. But a minor party that’s never likely to govern keeps seeing its painstakingly crafted press releases spiked, because these ideas are probably doomed to exist only inside someone’s head and most readers are drawn to stuff that actually touches their lives.

Lobby hacks will fight to get space for these more unusual stories, and occasionally even win. But the overall effect is that interesting but niche ideas get squeezed out, and minority parties are starved of oxygen. Unwittingly, the news agenda can end up rather like a sagging mattress where everything naturally rolls towards the middle, leaving voters on left and right with less orthodox views feeling excluded and ignored.

They might be wrong about why this happens, or deluded about how popular their ideas would actually be if given more airtime. But they feel airbrushed out of the conversation, and frankly they’ve got a point. The surprise is perhaps that it’s taken so long for their frustration to find an outlet.

The other effect of a journalistic bias towards winners, however, is that you tend to assume other people share it. Everything I ever learned covering politics suggested Corbyn wasn’t a winner – not just because of his ideological isolation but because of who he was.

He wasn’t a Michael Meacher or a Ken Livingstone or a Diane Abbott, leftwingers talented and ambitious enough to be offered frontbench jobs even when the prevailing wind was against them. He wasn’t a media-savvy John McDonnell. When you wanted a perspective from the left, there were better people to ask. He wasn’t even the left’s first choice to run.

And so to many commentators, his victory just didn’t compute. It made no sense. We treated it like a glitch in the system, almost a mistake.

Time may or may not prove it to be both those things, but in retrospect we could have been more curious about why those who backed him did so; we should be asking even now whether and why they still feel the same. (For every shrill social media warrior there are dozens of perfectly nice, normal people who backed Corbyn. They’re a lot more fun to ask.)

Jeremy Corbyn is not Donald Trump. But both are popular phenomena poorly understood – and in both cases, just shouting at people that they’re wrong has proved spectacularly useless. Asking them why they think what they think may not change anything much. But the conversation is sure as hell overdue.