It is possible that Sacha Baron Cohen’s Grimsby, a film that takes a blunderbuss to a conveyor belt of soft, easy and undeserving targets, has passed you by. In fact, judging by its poor box-office takings – even Sony’s spokesman admitted disappointment after it opened in the US last weekend – that is likely.

What you should know is that its lead character, Nobby, hails from the town that features in the title: a locale chosen by Baron Cohen for its name, after Scunthorpe failed the audition, and for what southerners like him perceive as its extreme Oop-North backwardness.

Nobby’s daily life of footie, beer, the pub, nice shag, bit o’ fookin’ draw, pub, kebab, chips, and four cans to go, etc, is presented to us with a relentless, leering smugness. When you laugh at it, you start feeling like Alan Clark MP cackling over the depressing tribulations of Eight Ace in Viz.

It never lets up. Nobby has 11 children, most of them shaven-headed and already tattooed. He is usually seen bar-side yelling for England amid a sea of drunks waving St George flags and wearing them on their faces. There is no culture but football. And bar-fighting. And lager. The womenfolk are a succession of trollops, drudges, chavs and slags, the men all bellowing yobs and lager louts, bloated and beet-faced with drink, semi-literate and narcotised by the telly. The kids live on the brink of criminality and anarchy. It’s a lumpen underclass, all living in their own private Asbo-zone, in a personalised rust belt shaped to exactly their needs. And it’s funny.

Except it’s not. It feels like a giant step backwards in time, utterly retrogressive in the context of a national film and TV culture that has diligently and sympathetically portrayed British working-class life in all its complexity, with all its ironies and tragedies, for decades. There is a lot of chaos and drinking in Ken Loach’s Raining Stones, but its characters are never belittled. They have inner lives, consciences, dreams, doubts. The same goes for the work of Alan Clarke, Dennis Potter, Peter McDougall, Mike Leigh and, more recently, Andrea Arnold, Lynne Ramsay and Shane Meadows.

There is a whole tradition of this that has faded in the collective memory as the years pass. Many of them told, as they were happening, the stories of how a once-robust and disputatious British working class was fragmented by affluence, riven by the dislocations of the 1970s, eviscerated under Thatcherism and its Blairite culmination, to the extent that the term “working class” became almost meaningless and obsolete, simply because there was no longer any work.

Days of Hope, The Price of Coal, The Spongers, The Boys from the Black Stuff: they all found poetry, wonder and soul in working-class life. And as This is England and Red Road prove, it can still be done. Grimsby, on the other hand, recoils from engagement and resorts to something like slander.

But should we be surprised by this tendency to punch downwards? It is after all, the common reflex of our times. Austerity politics are the ultimate version of punching downwards at a demonised, demoralised proletariat. It’s almost comical that the punching-down is all being done by Etonians in cabinet – comical as in, is it 1959 all over again, or 1939, even? And in a way, it is: all the institutional routes that ferried working-class kids into the middle-class in the 50s onwards – the welfare state, the National Health, free universities, art and drama schools, a decent dole cheque in hard times – all of that is gone, or hugely decayed. And I guess that, in the long term, when there is no one coming up from the Lower Depths any more to tell you what it’s really like, we end up with Grimsby. Or at Idiocracy, Or Berlusconi. Or Donald Trump.

Mike Judge’s Idiocracy sometimes felt as if it were punching downwards at poor white America, and its accelerating lurch towards barbarism. Actually, its satire was sharp, simply imagining what might happen if America just gave up, as it often seems to be on the verge of doing.

Judge’s co-writer Etan Cohen recently lamented that in 10 years, with the rise of Trump to the forefront of the Republican field, the whole movie had come true. President Camacho was Donald Trump avant la lettre. I see Idiocracy more as Judge’s satiric reprise of the Dark Ages that engulfed Europe after the Fall of Rome: history can run drastically, horribly backwards, and it may yet do so again, as Trump augurs daily.

A cynical appeal to working-class Italian nationalism and football-mania kept the ridiculous Silvio Berlusconi in office for a decade and more. How better to work up the rubes and the yahoos than by naming your fledgling political party after a nationalist football chant – Forza Italia! – with a decided whiff of Mussolini to it?

Trump has learned well the lessons of bunga-man. The Republican frontrunner also appears briefly in Grimsby, as he is infected with the HIV virus live on primetime TV. That joke – told with a reluctant caveat that reassures us he does not have Aids – plays on Trump’s well-known germaphobia, his dislike of personal contact, and his loathing for the huddled mass of losers, wimps, killers and rapists he perceives to be thronging at his castle gate, and from whom he has been utterly insulated – quarantined, even – since birth. His idea of the working class is: butler, chauffeur, waiter, doorman, pilot, poolboy, escort. When that fool bum-rushed him at one of his photo-calls last Saturday, you got a good idea of Trump’s feelings about the hoi polloi: that flinching spasm almost snapped his spine. If he wasn’t lampooned in Grimsby, I suspect he would love its portrayal of all those losers.

And yet here he is, a craven cynic, a man who has spent his life kicking and punching viciously downwards, who has routinely stigmatised “losers” and “wimps” and “crybabies,” says wages are too high, stiffs his workers and his “university” students alike, and uses the self-same cheap foreign labour he claims is killing the American economy, leading a People’s Soviet of splenetic working-class right-wingers, up to and including the Klan and a toothsome array of fascists and neo-Nazis.

But Trump’s followers are not all stupid, not all brimstone-gargling reactionaries and churchy hypocrites. The urge to hurl a fragmentation grenade under the tent-flap of the entire political-economic establishment is, at some level, perfectly understandable after years of war and economic catastrophe, largely visited upon the unluckiest among us. We have lived in a punch-down culture ever since the rise of Thatcher and Reagan. If we encourage and reward feral and bestial behaviour at the top, why should we be surprised when evidence of feral and bestial behaviour starts to mount up at the bottom of the heap as well? Up top, the insatiable corporate raiders and arbitrageurs; down below, the desperate 12-year-old street-corner crack dealer – proud exemplars of brute-force capitalism facing entirely different destinies.

But here we have a man punching down on Mexicans, the Chinese, blacks, women, losers et al, the better to inflame a sector of society that has itself been buffeted and dazed by decades of kicking and punching down. The solution, much beloved by poor Southern whites of the Jim Crow era: do some kicking down yourself.

And we should expect to see it replicated in our arts and culture as well, sooner or later. America has its own sins to atone for in the matter of lower and working-class cultural depictions – long the least visible demographic in American pop culture. We’ve had Cletus and Brandene on The Simpsons, the genial blue-collar idiots of My Name is Earl and Raising Hope, and every TV sitcom and drama has its underclass stereotypes, its hillbillies, crackheads, bums and welfare cheats.

Even Disney and Pixar’s animated works were recently chastised for offering unrealistic depictions of American economic expectations and class arrangements to the nation’s kids. In 1962, Michael Harrington, the last famous Democratic Socialist in America before Bernie Sanders, went into backwoods America in all its poverty and wrote the bestselling The Other America, which deeply influenced Lyndon Johnson’s massive War on Poverty, and inspired generations of activists for change. These days, when we venture into backwoods America, it’s with the retrograde, moronic Duck Dynasty. Things do indeed change.

But it can be done. It’s possible to portray the dispossessed or embattled (largely white) working class with sympathy, compassion, dignity and even humour. Mike Judge’s King of the Hill proved that for 13 years in one of the funniest, wisest, most beautifully and intelligently written sitcoms of all time, the Blue-state imaginations of its LA- and Austin-based creators (Greg Daniels being the other) reaching warmly and sympathetically into the Red state mindsets of Hank, Dale, Bill and Boomhauer. And it can be done with defiance, rage and beer-assisted pride, as in Pulp’s anthemic Common People, which revels in the endurance, stoicism, humour, and yes, unbridled hedonism of working people.

Grimsby could have used a lot more of that kind of sympathy and respect. So could we all.