I’ve been wondering how I would describe the sound MPs make during prime minister’s questions to an alien. It’s not a natural human noise – too joyless for a laugh and yet too lacklustre for a jeer. If a Foley artist had to recreate it for a film’s soundtrack, they’d fill an old accordion with gin and throw it down a flight of stairs – it’s the only way to get that thudding braying noise, wheezing out malicious approval like a drunk uncle watching Benny Hill reruns.

And yet the sound is also magic. When all MPs of a party make it together, like an oral conga line of partisan snarls, it can turn incomprehensible nonsense into a jolly good idea, a fine example of British wit. This has never been truer than on Monday, as it spun gold from one of the stupidest sentences ever uttered in parliament, when Iain Duncan Smith told the prime minister to “remind [the EU] that cakes exist to be eaten, and cherries exist to be picked”.

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As statements go, it’s not the most wrong thing that’s ever been said – cakes do exist to be eaten, and to an extent cherries exist to be picked (if he believes that the only function of nature is to serve humans, which, as a Thatcherite Tory, he probably does). But really it’s a play on the EU’s two criticisms of the British approach to Brexit: that we are trying to have our cake and eat it, and that we are trying to cherrypick the benefits of the EU without the responsibilities.

Instead of answering those criticisms, Duncan Smith has decided to purposefully misunderstand a set of very easy-to-grasp premises – and then pretended that this was somehow quintessentially British banter. It’s like a restaurant serving you a raw chicken because they claim not to know how an oven works, and then expecting a five star review on Zomato because the waiter said “methinks” when he served you the bill.

To be fair to the EU, the cake metaphor is a little confusing for some. They probably should have put it in terms IDS could understand, like: “You can’t impose benefit sanctions on someone who has already been killed by austerity.”

IDS is not the only politician to spout nonsense in the hope of stoking the prejudices of his supporters

But I don’t think Duncan Smith doesn’t really understand – which is much worse than if was completely incompetent. He knows that his comments don’t make sense – but he also knows they don’t have to. They just have to sound jingoistic and proud, and the logic can be drowned out by the sound of braying MPs and tedious tabloidisms.

“Parliament erupts in laughter as IDS taunts the EU” was the headline in the Express, the only approval that Iain Duncan Smith was really seeking. The only way that stupid line could have been more targeted at Express readers was if he had tattooed it on the back of a bulldog and finished it with “PS: the EU killed Diana”.

IDS is not the only politician to spout nonsense in the hope of stoking the prejudices of his supporters. They all do it – from Boris Johnson’s blase comments about the Northern Irish border, to bigoted-but-ironic-so-it’s-actually-hilarious Jacob Rees-Mogg’s wildly inaccurate claims about the Brexit bargains on big screen TVs, to John McDonnell’s deeply upsetting comments about Esther McVey where he claimed she was a “stain on humanity”.

They’re not saying these things to everyone – they’re saying them to their supporters, and they know that anyone else who hears and complains can be dismissed as traitors, scum or members of the “liberal elite” (which I think includes me, Hugo Rifkind and Stormzy now?). Only if they say something libellous do they retract them and Rees-Mogg can still do that in Latin, like the kooky, whimsical would-definitely-bring-back-hanging-if-he-could scamp that he is.

Welcome to politics in 2018, where there are no consequences for being bad at your job, or lying, or doing anything other than squawking misunderstood slogans in the face of facts. In some ways, it’s hard to actually blame these terrible politicians – it’s not their fault that every time they regurgitate some nationalistic Kipling-esque drivel about British trade deals, or lie about the status of Brexit reports, they fall upwards into a position of greater power.

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Years ago they would have been dismissed for failing to uphold the standards expected of MPs – but as the political centre has collapsed, so have the shared standards, values and responsibilities. There is no longer a “common” decency to judge them against – only a disparate set of partisan tribes.

We have created an environment which rewards bombast and bluntness, which punishes complexity and depth, which scorns compassion to those outside of our pack. For the most part, the only time we see opposing viewpoints is when they’re copied and shared in outrage as evidence of how ludicrous the other side is – which just sets us more staunchly in our ways, and makes us believe that those who oppose us are beyond redemption.

Ten years ago, I heard the sound of the braying MPs in PMQs and thought it sounded outdated, a tedious relic from a more boisterous era. Now I think it might have been ahead of its time: that cruel hollow laugh, designed to distract from the details, infects every part of the political debate today – and it’s letting the very worst people rise to the top.

• Jack Bernhardt is a comedy writer and occasional performer