It shouldn’t be remarkable, but it is. The prime minister’s suggestion that Keir Starmer, in his former role as director of public prosecutions, was responsible for the failure to prosecute the paedophile Jimmy Savile may soon be lost to the slipstream of political memory – but for a while, for more than a brief moment, it was met by a sustained chorus of anger and criticism across the country. The BBC made clear that there was “no evidence” for the claim; other broadcasters unequivocally referred to it as a “slur” in their headlines; the former Tory chief whip and House of Commons Speaker both publicly rebuked Johnson; even one of his most loyal aides, Munira Mirza, hitched her resignation to it. Behind the incredulous responses you could detect a sense of relief that “we are not there yet” – the “there” being a sort of post-Trump US, where QAnon conspiracy theories regularly make the headlines. But this is no moment for complacency. We are somewhere else, somewhere also troubling: a place where people are in denial about how Johnson’s Savile slur was the product of a political culture saturated with falsehoods, so often aimed at the political left and minorities. The wrongness of the Savile claim “cut through” because of the specific climate and manner in which it took place. The contempt for the man who made it, and his political position at the time – desperately lashing out to divert attention from his sinking premiership and sunken morals – made it seem lower and dirtier than if it had been made in any normal course of political business. The timing also amplified the claim, made as it was in a televised Commons session when the stakes were high, immediately after the release of Sue Gray’s damning “update”. Then there was the position of Starmer himself in this unique scenario, a protagonist sanctified in his role as representative of an angry and wounded nation. It was poor timing and optics on Johnson’s part. But, other than that, you can’t blame him for thinking that he would get away with it scot-free. All he was doing was taking part in a long, successful Conservative tradition that now involves shady extremists on social media, but has historically relied on a zealous rightwing press that brought us such smash hits as Ed Miliband, the son of the man who “hated Britain”. Let’s not forget that two Conservative prime ministers had either directly accused Jeremy Corbyn of being a “terrorist sympathiser”, or boosted claims that he had been a Soviet asset. In 2015, David Cameron called Corbyn a “security-threatening, terrorist-sympathising, Britain-hating” ideologue, using out-of-context quotes suggesting that the Labour leader was distressed by Osama bin Laden’s assassination, rather than the lack of any attempt to bring him to trial. When, in 2018, the Sun published an exposé asserting that Corbyn was a “paid collaborator” who had been “recruited” by cold war Czechoslovakian spies, Gavin Williamson, then defence secretary, ran with it. “That he met foreign spies is a betrayal of this country,” Williamson said. The Conservative MP Ben Bradley – in a since-deleted post, for which he later apologised, paying a “substantial sum” to charity – said that Corbyn had “sold British secrets to Communist spies”. When asked about the allegation, Theresa May said that Corbyn should be “open and transparent” and “account” for past actions. “The story lived on,’’ wrote the Washington Post, “provided oxygen by none other than Prime Minister Theresa May.” Cameron, whose political record in general has been buried under his colossal Brexit folly (better to be remembered as a fool than a knave), also enthusiastically embraced and promoted specious theories to support Zac Goldsmith’s London mayoral campaign against Sadiq Khan. He once said in prime minister’s questions that he was “concerned about Labour’s candidate as mayor of London” because he had “shared a platform” with a “radical imam”. Not only was that wrong: that very imam then told LBC radio that he was a Tory supporter, and felt rather bruised that he had been used to discredit Khan. Little of this is clever, studied stuff. It is more a strategy of throwing mud and hoping some sticks. If things get out of hand, then politicians soberly condemn the consequences with straight faces, as Johnson did when Starmer was harassed by anti-lockdown protesters who repeated, among other things, the Savile slur. When political rhetoric spills over into the real world, as it inevitably does, it’s attributed to an extreme minority of cranks – anti-vaxxers, lockdown sceptics, racists, loners and weirdos. But these people pick up their views from a larger cloud in which two fronts of misinformation constantly swirl – the demonisation of migrants, Muslims and other minorities, and the smearing of Labour politicians and leftwing movements as anti-British. Driving these winds is a poorly regulated press prone to having ideological motivations at worst, or being straight-up gullible at best. The Sun can publish a far-right conspiracy about a “hard-left extremist network” at the heart of the Labour party, and then delete it before the day is out, with no explanation or, more crucially, much outrage. The same goes for discredited front-page stories about Muslims fostering Christian children, and faked “plots” to take over British schools. It’s hard to look at the past decade and conclude that Johnson’s Savile slur came out of a clear blue sky. It’s a good thing that many were appalled by it, but that’s of no use if we are going to continue to be selective about which falsities we let slide in the future. It will happen again. Even Starmer’s amnesty is fading. Despite the force of the pushback to Johnson’s lie, the machine is already mobilising to defend and launder it. Before long, it will probably pass into the realm of vexatious and plausible tropes tarring the Labour party. That’s not Johnson’s or the far right’s doing alone. The truth is that, deep down, too many people who aren’t radicalised or conspiracist think targets of smears are somehow fair game, perhaps not guilty of this or that particularly outlandish offence, but generally flawed enough for lies to capture a wider truth about them. The natural outcome of this is the entrenchment of a political culture in which dangerous untruths are rife and rarely challenged. Either every one matters, or none of them do. Nesrine Malik is a Guardian columnist