When the late great Peter Cook opened The Establishment, London’s first satirical nightclub, back in 1961, he said its inspiration was “those wonderful Berlin cabarets which did so much to stop the rise of Hitler and prevent the outbreak of the Second World War”. Of course this was just a joke, but Cook’s point was clear.

Satire was fun, but it had no power. Thirties Berlin had been full of brilliant satirists, but their humour made no difference. For Berlin in the 1930s, read London in the 1960s. Cook’s club would poke fun at the British Establishment, it would lampoon the hypocrisies of our leaders, but he had no illusions that it would change anything at all.

Peter Cook poses in a BBC studio in 1964 (Getty ) (Getty)

Cook was wrong. Sixties satire did make a difference. A host of young satirists brought about a lasting change in British society, and Cook (who also owned Private Eye) was the leader of the pack. In the satirical stage show, Beyond The Fringe, he became the first performer to impersonate a British Prime Minister, Harold Macmillan. When Macmillan, came to see the show, Cook mocked him to his face.

Private Eye’s front cover this week

Cook’s iconoclasm changed the climate. No longer did we regard our leaders as our betters. Macmillan stepped down in 1963, and in 1964 his Tory successor, Alec Douglas-Home, was ousted by Harold Wilson’s Labour Party. The Age of Deference was over. From That Was The Week That Was to The Frost Report, satire reigned supreme.

For the past fiftysomething years, ever since Cook’s success, we’ve believed in satire – and with good cause. Satirists had the ability to shape events, or so it seemed. Ridicule was a lethal weapon. David Steel never recovered from his portrayal on Spitting Image as David Owen’s puppet. When John Major became a figure of fun, the Tories knew the game was up.

But now a politician has come along who confounds this rule of thumb, and his name is Donald Trump. Throughout his first year in office, he’s been subjected to the most ferocious satire, and it’s clearly had no effect. What’s going on? How can a man who’s routinely depicted as an idiotic charlatan remain unharmed by such a tidal wave of comical abuse?

Donald Trump’s immunity to satire is a sign that politics is changing, and the thing that’s changed politics most of all is the fragmentation of the media. In our digital age, with countless TV channels and Twitter feeds to choose from, mockery no longer matters – brand recognition is all that counts. Tempted to post something critical about a company you dislike on the internet? Don’t bother.

It’ll merely push their website up the charts, and onto the front page of your search engine. The same goes for Trump. We all laughed at Alec Baldwin’s impersonation on Saturday Night Live, but it kept Trump in the news and gave him a stature his opponents lacked. Do you remember Morgan Spurlock’s 2004 documentary about McDonald’s, Super Size Me? Sure, its conclusions about fast food were chilling, but didn’t it make you want to eat a Big Mac?

The other thing that makes Trump immune to satire is that he’s an Us-And-Them politician. While moderates try to find common ground, reaching out to floating voters, Trump delights in building walls between his supporters and his opponents. He relishes confrontations with the so-called “liberal elite” – it creates a siege mentality, and consolidates his core support. For his Midwest fanbase, what could be more confrontational than a bunch of elitist TV stars in the Democrat strongholds of New York and California saying their President (and, by inference, anyone who voted for him) is a bigot and a fool?

The Slovenian philosopher Slavoj Zizek nailed this anomaly in an interview with the BBC last year, when he drew an intriguing comparison between witty commentators like John Oliver and Jon Stewart and populist fake news. “Isn’t the liberal left engaged in something quite similar?” he argued.

Margaret Thatcher and John Major depicted in the Eighties show ‘Spitting Image’ (Rex) (ITV/REX)

“This is the ultimate failure of the left for me – patronising, making fun of ordinary people.” Zizek is horrified by Trump, but he recognises Trump’s success in connecting with ordinary Americans who feel abandoned by mainstream politicians, and he sees wags like Oliver and Stewart as a sign of the liberal establishment’s impotence against this existential threat. If you didn’t vote for Trump, watching Oliver or Stewart will make you feel good about yourself. But what if you did? Will it really make you change your mind? Or will it make you even more determined to vote him in again next time?

In Britain, the closest thing we have to Trump is Brexit, and the same logic (or lack of it) applies. Comedians cracking jokes about racist or ignorant Leavers is great news for Brexiteers. They need to lock in that 52% who voted Leave, and make sure they don’t change their minds. What better way to do this than to keep subjecting them to lots of “Remoaning” metropolitan abuse?

When you look at the way Trump (and Brexit) have weathered such savage invective over the course of the past year or so, you begin to wonder: does satire actually do more harm than good? It’s a question Malcolm Gladwell explored in his excellent Revisionist History podcasts. Gladwell called it The Satire Paradox, and his conclusions are disconcerting. It seems satire creates more heat than light, and the noise it makes is neutral: you may think Baldwin’s Trump impression confirms The Donald is unfit to be President; for his supporters, the same sketch may merely reinforce their gut feeling about what a great guy he is. Anyone who’s sat in a comedy club and watched a comic doing edgy material will know that two people in the same audience can be laughing at the same joke for completely different reasons.

Cartoon published in 1980s Iranian satirical weekly ‘Asghar Agha’ published in Britain by Hadi Khorsandi (Asghar Agha)

Gladwell cites the case of Loadsamoney in his podcast – Harry Enfield’s comic caricature of brash working class consumerism in Thatcher’s Britain, which was embraced by the people it set out to satirise. Gladwell could have mentioned Alf Garnett, who suffered the same fate a generation earlier, when Johnny Speight’s portrait of an East End bigot (portrayed by Warren Mitchell) was championed by its targets. Margaret Thatcher was impervious to satire, because the satirists focused on her strengths. Likewise, it’s useless mocking Trump’s inability to construct a coherent sentence, when his main selling point is that he’s not remotely sophisticated, erudite or intellectual.

So what’s the answer? Should commentators ditch the jokes, and focus on serious investigative journalism instead? Most disquieting of all, it seems even hard-hitting reportage suffers from what we might call the Trump Paradox: the more you talk about something, however negatively, the more popular it becomes. This phenomenon has been exacerbated by the internet, and Trump’s divisive personality, but it seems it was ever thus. In The New York Review of Books, Adam Hochschild, who teaches journalism at the University of California, cites a Pulitzer Prize-winning expose published way back in 1921, in a newspaper called the New York World, about the secret rituals and violent crimes of the Ku Klux Klan. “The heavily promoted articles ran for three weeks, were reprinted by 17 newspapers throughout the country, and provoked a congressional investigation,” writes Hochschild. “But instead of crushing the organisation, the expose did the opposite; one historian estimates that the series increased Klan membership by more than a million.”

Ironically, it’s refugees from countries where free speech is prohibited who seem to value satire most of all. Exiled Iranian journalist Hadi Khorsandi (father of stand-up comic Shappi Khorsandi) once observed, “In Iran there is freedom of speech – but no freedom after speech.”

His critiques of the Islamic Republic in the Eighties – in Asghar Agha a satirical weekly he published in the basement of a newsagent in Ealing, west London – drew the wrath of Ayatollah Khomeini himself in the shape of a death warrant, according to his daughter. In 1984 British intelligence intercepted two assassins who had been sent for him. In 2006 he told CNN, “Satire destroys the present image in order to make way for a better world”. I wish I could share his optimism. Personally, I’m beginning to wonder whether satire is actually worse than useless. On reflection, it looks like Peter Cook was right after all. Maybe if those Berlin cabaret clubs had stuck to nude revue, Hitler might have got bored of politics, and gone back to landscape painting.