Since the Labour party conference roared to its triumphant close just over a week ago, a 90-second video has been punted around Twitter and Facebook featuring the indomitable MP-cum-national treasure Dennis Skinner. On YouTube, the clip is headlined “Dennis Skinner schools a journalist”, and the qualities he always brings to his interviews are present and correct: hardened principle, a spirit of fierce defiance, and his own kind of high camp.

The man Skinner is talking to evidently wants to indulge a familiar trope, asking whether Labour’s high spending plans reflect a failure to learn the lessons of the past. “No, no, no,” says Skinner – and as Labour people often do these days, he then goes straight back to 1945. “As a matter of fact, do you think it was wrong for Nye Bevan to build the health service, to save your life? Or your relatives’ lives?” He mentions the postwar building of council houses, and says unemployment in the same period ran at 2.2%. “Do you agree with that?” he says. “Answer!”

“I’m just here to ask questions,” replies his inquisitor.

Even partisan commentary can be rooted in the principles of good journalism if it does not ignore uncomfortable facts

“You think you’re asking awkward questions,” says Skinner. “So why don’t you understand that you are part of society … It’s time that you understood that you’re not somebody outside the perimeter. You’re involved … But somehow, you people connected to the television [and] media, you think you’re above it all. You’re not! You’re more and more like Trump. You’re vain! Conceited! You believe that no one should argue with you!”

God bless Dennis and all that, but after two weeks spent visiting both main parties’ conferences and once again talking to the general public about Brexit, this kind of stuff has started to grate.

From the ecstatic noise around Jeremy Corbyn to those slightly desperate Tories who now swoon at Jacob Rees-Mogg, British politics is newly alive with passion and ideological division. The wider world reflects much the same picture: even on high streets in Kent and Greater Manchester, one can sense the same kind of fevered polarisation – so that, as I discovered in Gillingham last week, asking even mild questions about the consequences of Brexit occasionally invites such ripostes as, “You’re a remainer, aintcha?” In that kind of highly charged atmosphere, to be a journalist, looking askance at the drama and divining contradictions and inconsistencies as much as chronicling all the fervour and emotion, is to be hopelessly out of step – and, in some cases, to find oneself at the receiving end of derision and hostility.

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At the more extreme end of all this sit such demagogues as Putin, Trump, Erdoğan, and the Hungarian leader Viktor Orbán. The latter is now in the habit of associating the media with a “mafia network” supposedly commanded by the financier George Soros – there are, obviously, antisemitic overtones here – and encouraging sympathetic online outlets to accuse journalists of something close to sedition. The essential argument was recently laid out by an outlet called 888.hu: “The international media, with a few exceptions, generally write bad things about the government because a small minority with great media influence does everything to tarnish the reputation of Hungary in front of the world – prestige that has been built over hundreds of years by patriots.”

Here, British understatement might get in the way of such rhetorical melodrama, but there are shades of much the same mindset. On the political right, there is the belief that the media are miserablist anti-patriots (or, if you prefer, citizens of nowhere), as highlighted by Liam Fox’s recent claim that the BBC is guilty of reporting Brexit with a tone of “self-defeating pessimism”. On the left, meanwhile, there is an ingrained belief that even self-consciously impartial coverage only thinly conceals the agendas of neoliberalism, and what is known these days as “centrism”, and that the mask regularly drops.

We can no longer pretend the British press is impartial | Owen Jones Read more

The fact that the BBC’s Laura Kuenssberg was accompanied to Labour conference by a bodyguard barely needs restating. But even after that had become clear, the dependably unrestrained Corbyn-supporting outlet the Canary reported that the BBC editor was listed as an “invited speaker” at a Conservative fringe meeting, with the headline: “We need to talk about Laura Kuenssberg.” The same, it quickly turned out, was true of my colleague Owen Jones, but that did not seem to get in the way: despite the absence of corroborating facts, the Canary was once again of the opinion it had punched through the “impartial” veneer, revealing the true-blue agenda beneath.

What is going on here? Clearly, the idea of journalism as a cover for this or that agenda is hardly new. In many instances, as a quick trip to the newsagents will confirm, the accusation has long been justified. But there again, even in the kind of outlets seen as bywords for propaganda and partisanship, the journalistic impulse is alive and well (if you doubt this, consider the estimable coverage of industrial disputes in the Morning Star). Even partisan commentary can be rooted in the principles of good journalism, so long as it does not ignore uncomfortable facts, blindly offer support to parties or leaders, or distort actuality to score political points. More than that, though, the idea of journalism as a route to the truth is every bit as worthwhile as it ever was.

But it is also under threat. In the Facebook age, outlets that value the idea of dispassionate inquiry and dogged research are feeling the pinch, while a great ocean of polemic, often written for nothing and barely interested in the world’s endless complexities, grows ever larger. The polemicists have a symbiotic relationship with the wider political mood, feeding off all the passion and emotion, and then doing their best to ramp everything up. As all that happens, the distinction between activism and journalism becomes dangerously blurred. Even among people fresh out of university, the “in” thing is seemingly to be a pundit rather than a reporter; in the online world, there are rather too many polemicists, and not nearly enough journalists.

Laura Kuenssberg hiring a bodyguard was depressing. Then it got worse | Gaby Hinsliff Read more

As evidenced by new media platforms on both left and right, there is a kind of outlet that fits snugly into this new world. It decries supposedly objective stuff as hopelessly biased while claiming that its own overheated polemics shine much brighter light on the truth. Put another way, as the Times columnist Hugo Rifkind recently said, “it’s a defining feature of the Canary/Evolve/Breitbart/Westmonster axis that they cannot comprehend [the] difference between analysis and advocacy … So they think their own advocacy is analysis, and regard the analysis of others as advocacy.” The basic belief, which anyone who has studied postmodernism would understand, is that even the most dispassionate journalists are guilty of bias, and everything ultimately blurs into a cacophony of partisan shouting.

As a principled socialist such as Dennis Skinner would surely recognise, this points to a dangerous future: of endless conflict, power not held to account, and vested interests free to run riot. The election of Trump and our collective failure to comprehend the insanities of Brexit suggest we may already be halfway there. So how do we pull back? The answer lies with those much-maligned people outside the perimeter, asking awkward questions, trying to maintain some imperfect balance between opinion and truth, and scribbling into their notepads.

• John Harris is a Guardian columnist