One TV moment from the last few acrid weeks lingers in the mind. Theresa May, on that ill-fated first visit to Grenfell Tower, is being hustled towards her car, pursued by a crowd of journalists. And there’s a television reporter at the back, shouting loud. “Why are you running away, prime minister?”

Now, perhaps we’re used to this shouting gambit. Even the likes of Laura Kuenssberg and Nick Robinson use it from their Downing Street holding pens. “Are you going to resign?” “Is that the end of austerity?” Questions bellowed into the ether, not expecting an answer, as the PM turns her back. Questions adding a little drama to keep the camera boys happy.

But see how such empty bellowings fit into a pattern. Across the Atlantic, the president tweets about a news anchor’s bleeding plastic surgery wound, then video-wrestles with a mock-up of the CNN logo. A Republican congressional candidate body slams a Guardian reporter. And the White House opts for controlled words, rather than pictures, at briefing time as Trump develops a special relationship with the supermarket sleaze of the National Enquirer.

It’s a development prompting countless articles about the death of press freedom and allied issues. And, of course, the pattern reaches much closer to home as the assorted essays in a new book called Brexit, Trump and the Media (published by Abramis on 6 July) amply demonstrate. Everything connects.

Trump is a phenomenon who still, almost nine months on, retains the basic allegiance of those who made him commander-in-chief. But don’t inane tweets, Russian scandals and foul bluster drag him down? On the east coast and west coast, maybe. But still base-camp middle America stays loyal. Millions there don’t join the hubbub of distress because, simply, they don’t much read or watch the nation’s media; and, when they do, they don’t trust it. They exist in their bubble of belief.

You can find exactly the same fractured dialogue in Britain, too. What did the surprise of the Brexit vote show? Here’s another tidal wave of articles talking about the non-metropolitan forgotten masses. That, briefly, seemed a national call for understanding and change, one inchoately confirmed in the June election. But see how deafness and disdain soon set in.

Let’s blame something – Boris, Rupert Murdoch, Paul Dacre, the BBC – for Brexit. Let’s contemplate the rise of Jeremy Corbyn and press a panic button. The Mail talks about “fake news, the fascist left and the REAL purveyors of hate”. Guardian columnists denounce the “open sewer” of Dacre coverage. Terms like “Tory scum” float from protesters’ posters into the new mass media. Jon Snow, amongst others, gets pasted for his supposed views about modern Conservatism. Irate Leave MPs stomp on the BBC welcome mat.

There is a feeling that Trumpworld, with its normalised contempt, is infecting areas far beyond National Enquirer land.

And every new day seems to bring fresh ingredients. Kensington council seeks to shut journalists out of its crucial meeting. Andrea Leadsom extols a “patriotic” press. There’s a raw edge to the debate now, sharpened after Grenfell Tower by outbreaks of pure and, sometimes, simulated rage. But: “Sit up, though, and look around. You may notice that, amid almost no public outrage whatsoever, we are quite a lot closer than once we were” to losing press freedom, says Hugo Rifkind in the Times.

This is politics, and journalism, from the trenches as trust in the media plummets both here and in the US: American trust in the media down to just 38% in the latest Reuters Institute findings, the UK seven points down to 43%. Blame “deep-rooted political polarisation and perceived mainstream media bias”, says Reuters. In short, blame the frenzied state we’re in.

Does this, though, mean the Labour and Tory MPs who habitually share croissants and orange juice with Robert Peston can’t be civil, or even friendly? Of course not. That’s the nature of the Westminster club, where much of the public hatred turns to relaxed toleration in private – while Mail and Guardian hands can sit side by side in the press gallery. Reality isn’t a high-pitched scream of fear and loathing.

But observe how the new nihilism of scum and sewers brings its own narrow benefits. Richard Cohen in the Washington Post arrives clear-eyed. “Circulation is up. Eyeballs are popping. Trump is political pornography – gripping, exciting, lewd, fascinating. He devours adjectives so that, soon, we run out of them. The bizarre becomes ordinary. But he has done his damage. He has normalised contempt for the news media, framing it as a daily tussle between him, the tribune of the people, and us, vile overeducated snobs.”

And Jeet Heer of the New Republic pushes the argument on a notch as he charts the advantage of Trump’s alignment with the likes of the National Enquirer: “The tabloids offer a sordid vision of society, where the mainstream image of celebrities elides their secretly miserable lives (whether because of addiction, ageing, infidelity, or bankruptcy). In this nihilistic world, everyone is corrupt and every public statement is a lie. And if everyone is equally bad and untrustworthy, there’s no reason to hold Trump to any higher standard. This, ultimately, is why Trump and the tabloids were made for each other: They’re both committed to defining deviancy down.”

Too apocalyptic? In one sense I’ve always thought that “trust”, as a media commodity, has to be earned story by story. No saintly, all-purpose balloons of the kind BBC audience surveys suggest. But there is now a feeling that Trumpworld, with its normalised contempt, is infecting areas far beyond National Enquirer land. The invective is rawer. Anger flows faster. “Are you running away, prime minister?” Not if Mrs May and the reporter shouting his lines value what remains of our tattered democracy – and the press freedom that walks with it, side by side.