As you may have noticed some of the mainstream media are slightly hostile and critical,” the politician tells a rally of the faithful in Broxtowe. They laugh, indulgently. “They’re very unkeen on relating to the issues people face.”

He decides to single out one media organisation that has particularly displeased him: “I did an interview with Sky last night. It was 14 minutes, the interview. We got to, I think, minute 12, before I intervened and said, ‘Is there any chance that anybody other than an MP could be referred to in any of your questions?’” The crowd are clapping heartily by this point. “And we could actually talk about the homeless, the poverty, the hospital waiting lists.”

A few days earlier, another politician had similar thoughts. “You know, some of the most dishonest people in media are the so-called fact-checkers,” he said at a rally in El Paso, Texas, on 11 February. “We have suffered a totally dishonest media and we’ve won and it’s driving them crazy.” Reporters were shoved and barracked at the rally, and a BBC cameraman was assaulted. Later, after the politician was accused of corruption, he singled out one news organisation that had particularly displeased him: “The New York Times reporting is false. They are a true ENEMY OF THE PEOPLE!”

You don’t need me to tell you that one of these politicians is Donald Trump and the other is Jeremy Corbyn. Both have made criticisms of “the mainstream media” or “the fake news media” part of their pitch – an easy way to fire up a partisan crowd. Both demonstrate absolutely zero hygiene in trying to separate unfair, hostile headlines from legitimate scrutiny. The only conclusion, in both cases, is that they do not believe legitimate scrutiny can exist.

Where Trump is brash and bombastic, Corbyn is pious and petulant. He is so convinced of his own righteousness that any criticism prompts self-pitying rage, barely smothered into a clipped “OK?” He is not a pacifist, except where the wars involved are led by America. He is only a lifelong campaigner against racism if you exclude Jews from the category of oppressed groups. He shares a desire for victimhood with the worst parts of the British right, who dismiss any concerns over a no deal Brexit as “Project Fear”. Both appear to expect belief rather than just support.

Most troublingly, Corbyn’s left-wing populism tips into an alarming form of authoritarianism. News of the violence and repression in Venezuela sent me back to watch Corbyn’s chummy phone-in chat with Venezuela’s president Nicolás Maduro in 2014, about his mentor Tony Benn. (Maduro has his own lengthy television show, which is a totally normal and not even slightly dictatorish thing to have.) And I thought: what a shame they didn’t have time to get on to the mainstream media. They would have had so much to talk about. On 12 February this year, Maduro told the BBC’s Orla Guerin that she was wildly misrepresenting the state of Venezuela, because “you are the Western media, because you are in the script, to intervene in our country”.

Maduro is following the propaganda template laid down by his predecessor Hugo Chávez, who insisted that TV and radio schedules be cleared for obligatory broadcasts – cadenas – every time he wanted to tell Venezuela what was on his mind. Handily, such broadcasts could also be timed to coincide with opposition rallies, denying them coverage.

In his BBC interview, Maduro said that food and medicine shortages were overstated, part of a “campaign of media aggression, of lies” and that he would “slowly start to conquer them with reality”. He did not like it when Guerin gestured to undeniable facts – the 50 governments that have recognised his rival Juan Guaidó as the legitimate leader of the country, for example. The numbers were false, he said, any “objective journalist” could see that. Instead, she had come to Venezuela “to verify your war campaign, the BBC’s war campaign, and the Western campaign against Venezuela”.

Again: there can be no scrutiny. Criticism is illegitimate by definition. Journalists are enemies of the people. If a journalist accuses Trump of lying, it’s because of their liberal agenda. If a journalist accuses Maduro of presiding over hunger and sickness, they must want to enable an imperialist invasion. If a journalist wants to talk about anti-Semitism in the Labour Party, it can only be because they love austerity and hope hospital waiting lists increase.

By attacking the media, all three men – Corbyn, Maduro and Trump – know exactly what they are doing. Any journalist’s defence of the profession can be dismissed as special pleading: you would say that, wouldn’t you? It’s a cheap trick that works because everyone hates journalists already. Look at them, sitting there in London, earning a packet, not meeting “real people” (whoever they are). This lazy criticism conflates megabucks contrarian columnists with the majority of the industry, where salaries are low and employment is precarious. There’s a reason that the PR business is full of ex-journalists. Puffery pays better than takedowns.

The irritating thing is that if Jeremy Corbyn genuinely wanted to improve the media, I would support him wholeheartedly. There are numerous structural problems. The printed press is not diverse enough, in either ideological or demographic terms; the BBC often follows an unthinkingly pro-establishment line; local papers are dying out; court reporting is dwindling to nothing; and monopolies must always be guarded against.

But that’s not what gets Corbyn’s engine running. He hates his deputy, Tom Watson, who has done more than any other politician to check the power of British newspapers. It is partly thanks to Watson that one phone-hacking newspaper no longer exists, and another has paid out millions of pounds in damages. Time magazine described him as the “man who humbled Murdoch”.

Alas. Watson is one of “them”, part of the ancien régime who must be erased from history, so his concrete (and controversial) proposals have been put aside. Instead of policies, we get punchlines. Corbyn begins almost every speech with a knowing dig at the media, in the same way that Trump mentions the Mexican border wall for guaranteed applause. That shows the Labour leader’s attacks are really about identifying an enemy – and inoculating his most faithful followers from ever contemplating the possibility that he might be wrong.

In his 2018 party conference speech, Corbyn called British newspapers the “propaganda of privilege” (fair) before hailing social media as a better form of modern communication. Which particular social media network does he mean? Facebook, where conspiracies spread like forest fires? Twitter, where death threats and harassment are commonplace? YouTube, where you’re never more than six clicks away from a video explaining why 9/11 was an inside job? Perhaps Snapchat or Pinterest will be the saviours of the left. Be real: social media has structural problems, too, but they are newer and shinier and so easier to ignore. Plus, Momentum do lovely viral videos.

I watched the Sky interview that Corbyn complained about, by the way. The interviewer, Lewis Goodall, asked him why nine MPs had left his party, which feels like a reasonable line of questioning in a week where nine MPs had left his party. At the start of the tenth minute, Corbyn says that “you and your splendid colleagues in the media only ever talk about Westminster gossip; you never, ever talk about what’s happening outside”. See what I mean about the lack of hygiene? He should be sentenced to watch every single John Harris video. It suits Corbyn to pretend that op-ed columnists and lobby reporters are the entirety of the political media. There’s no space in his world view for, say, the Victoria Derbyshire show’s moving series on children leaving care, or James Meek’s elegant LRB essays on the future of the NHS and similar subjects. Or indeed our own Anoosh Chakelian’s reports on austerity Britain.

Journalism is not PR for politicians. (There are only four paragraphs on homelessness in the 2017 Labour manifesto, which notes: “There can be no excuses – it must end. Full stop.” That kind of overwrought rhetoric usually disguises a lack of actual policies.)

As for hospital waiting lists, it was a BBC investigation last autumn that uncovered the fact that a fifth of NHS trusts had missed all their targets. This news was ruthlessly suppressed by right-wing outlets such as the Telegraph, which ran it under the headline “A fifth of NHS hospitals are missing all their waiting list targets this year”. Labour’s policy on waiting times is to cut them – guaranteeing treatment within 18 weeks – by giving more money to the NHS. One way to raise awareness of this would be for Corbyn to mention it at the very start of his speeches, perhaps in the portion of time usually allocated to criticising the media.

A political interview is not an opportunity for the speaker to air prepped soundbites to a grateful nation. The idea is to probe weaknesses and uncover inconsistencies. Anyone who is aware of the threat to democratic norms posed by Trump must see the parallel with Corbyn’s thoughtless media-bashing. I worry, though, that they feel the end justifies the means: the destruction of objective reality is a small price to pay for a Labour government. And, by the way, we invited Jeremy Corbyn to write an article or be interviewed in the New Statesman this week. We had no reply.

The glib menace of that Maduro interview should be a warning to all British journalists. Who would have the right to tell Prime Minister Corbyn he was wrong? Oh well. I suppose I’d better get used to being an enemy of the people.