The ejection of Sarah Huckabee Sanders from a Virginia restaurant, by staff unhappy at her role as Donald Trump’s spokeswoman, has crystallised an American crisis: not quite a civil war but a civility war. According to the Trump administration, an epidemic of bad manners, mockery and profanity has taken over its opponents.

Disparate incidents of opposition to Trump and his regime – including barbs by TV comedians – are being collapsed into a single story: a pouty, entitled and bad-loser left is abandoning civility, and in doing so inciting hatred and violence. Some of this hyperbole about a crisis of manners is cynical political point-scoring. But much of the rest shows a blindness to the fact that the sort of civility being mourned – the kind that meant politicians could go about their business without fear of abuse from the public or the president – broadly did exist before Trump hit the campaign trail and began beating the drum of misogyny, racism and hatred of the press. It was called political correctness, and Trump supporters didn’t like it.

In fact, Trump made opposition to it one of his flagship election policies – no more being nice to people just for the sake of it. During the first debate of the Republican primaries, Fox News host Megyn Kelly asked Trump how he would answer the charge that he was “part of the war on women” (he had called women he didn’t like “fat pigs”, “dogs”, “slobs”, and “disgusting animals”, and had told a contestant on Celebrity Apprentice it would be a “pretty picture to see her on her knees”). “I think the big problem this country has is being politically correct,” Trump answered, to audience applause. “I’ve been challenged by so many people, I don’t frankly have time for total political correctness. And to be honest with you, this country doesn’t have time either.”

And the country, the part of it that voted for him and continues to support him, concurred. It does not have time for a political correctness that prevents men from calling women dogs, from mocking disabled people, from insulting those they disagree with as having a low IQ. The end of civility was what Trump promised, and what his voters had wanted for a long time. Trump’s country has no time for sympathy for families separated from their children, if it stops migrants smeared as rapists, drugs dealers and murderers getting into the country; it has no time for the victims of school shootings if it means curbing the right to gun ownership; it has no time for a free press if it means having to be presented with facts that counter its claims.

And yet, the response to this promised vandalism of manners, decay of tone and disregard for human life has sent Trump and his supporters into a swoon of offence. A text message sent to Trump voters last week asked for financial support because it was “time for civility”, and time to “show the left we won’t be intimidated”.

The Trump era has provided a whole lexicon of euphemistic terms whose real meanings must be deciphered. “Rust-belt” voters, those suffering “economic anxiety”, “real Americans”, are some of the descriptions that mean “white people who voted on the basis of racial grievance”. “Political correctness” as deployed by the right generally means being denied the right to use demeaning language, and in turn treatment, against minorities and women.

Yet at heart, the point of political correctness is to foster a framework of sensitivity towards the weak or the vulnerable who are too often stigmatised or excluded. But the Trump agenda thrives on exclusion, on seeing others as inferior, and so time was up for political correctness because it extended the right of politeness and respect to everyone. It is now “time for civility”. In the Trump dictionary, this means it is time for the hierarchy to be restored and for decorum to flow only one way – upwards, towards those in power, towards the white and the male.

This is not solely Trump’s innovation. His style is to act as a parasite, to feed on all the cultural grievance effluvia of the past few years, synthesise it into something toxic and incendiary, and then spread it. He gave himself, and by extension his supporters, the permission to unleash prejudice, bigotry and resentment – branding it as a liberation from the suffocating PC culture.

This is the culmination of a long campaign that can be traced back to the early 1990s in the US, when a wave of stories and reports began to appear in the press, panicking about how US universities were succumbing to pressure to conform to liberal agendas about race, ecology, feminism, culture and foreign policy. Long before political correctness had even become a mainstream concept, it was reported as an established ideological zealotry.

Today the person most responsible for any zealotry is in fact the president himself. Any questions of how vitriol becomes a gateway to violence should be directed at the Trump administration – under which white supremacists, “very fine people” according to the president, openly congregated in the streets and a protester was killed; whose invective towards the press led to journalists having to be escorted by security to their cars during Trump rallies; and where high school gunmen wear hats bearing his “Make America Great Again” slogan.

What happened to civility? Trump supporters didn’t realise it was in fact, at heart, political correctness, and they voted it out.

• Nesrine Malik is a Guardian columnist