“Looking at the Brexit vote now, it was a precursor to some extent of what happened to us in the United States,” Hillary Clinton told the BBC’s Andrew Marr. When President Barack Obama came over just before the referendum to plead with our better natures and warn of an outcome which he elegantly understated the catastrophe of, it felt a little shaming, like a grownup arriving in the middle of a food fight. Clinton, partly because she isn’t president, mainly because those Brexit and Trump ships have sailed, appears less like an authority and more like a coroner at an inquest.

Her third argument is to remind us how extraordinary it is, how unprecedented, how eerie, that they “just elected someone who admitted sexual assault to the presidency”.

Arguments belonging to the middle of the last century resurface. Are women fit for public office?

Leaving the EU, voting for an aggressive and unstable reality TV star, holding women in contempt: there is no obvious logical connection here, no strand of ideas that takes you from the Singapore free-trade fantasies of hard Brexiters, to the protectionism of Donald Trump, to the new misogynist mood music that enables our foreign secretary to dismiss the disquiet about a sexual predator in the White House as a “whinge-o-rama”. Yet we know instinctively that these positions are connected, that the chauvinism which turns women into objects exists in the same mental frame as fixing on the immigrant as the enemy, or the Muslim as the source of all violence.

Clinton’s linking mechanism, between our politics and hers, was pragmatic: both the EU referendum and the US election were poisoned by fake news. A big lie can get you a long way in politics, especially if all the usual defences against it – a competent and passionate opposition, a sober and neutral media – have miraculously evaporated. Certainly, the legitimacy of a result won by falsehood is questionable; and yes, the internet, in its impact on democracy, is not looking like an untrammelled boon.

Yet there have been communities creating fake news since the dawn of time. At any point in history when hatred has been generated to persuasive effect, you would have found somebody, somewhere, cobbling together some nonsense about the death of a child or satanic rituals or improper use of emails. Far more novel than fake news is the expectation that published matter should be true, which is less than two centuries old.

The important shift over the recent past is not the explosion of misinformation but the willingness of politicians to spread it. The rules around respectability used to be pretty clear on this: you could use facts selectively to make your case, conveniently ignore those that didn’t suit it, possibly amplify, maybe bluster a bit. But you did not, in public office, say a thing you knew to be untrue. To do so would mean relegating yourself from the ranks of the serious, into the more Mike Fabricant-ey realm, where you yell “bollocks” in parliament and dream of punching journalists in the throat, and nobody minds because there’s only one of you and you have funny hair.

The £350m NHS claim, now, is only the flagship lie. It has become quite routine for facts to be misused or waved away, for experts to be dismissed and inconvenient truths rejected as sabotage or treason, by quite senior figures in public life. It is pretty normal for members of government to use words to mean the opposite of their definitions, “parliamentary sovereignty” when they mean “parliamentary submission”, “overwhelming majority” when they mean “very slim majority”. What inoculated the political culture from falsity was not a shortage of it, but the standards politicians held themselves to.

It wasn’t perfect; dishonesty happened in the wings – but not on the stage. What drives this new impunity is not scorn for the truth but a contempt for pluralism. In a debate proceeding along pluralistic lines, compromise is expected, different perspectives are welcomed, sustained argument is understood as a creative process leading to greater wisdom; and the foundation for it all is a shared set of facts.

If you want your debate to proceed along authoritarian lines, where the winner takes all and the loser shuts up, the first thing to eliminate is that shared space called reality, where everyone has access to the same information and agrees on its veracity. When Trump lies on Twitter, whether it’s about how many times he’s been Time magazine’s cover star, or the size of his inauguration crowd, it’s not by accident: he is explicitly rejecting the audacity of the demand that he be tethered by argument. It doesn’t matter what’s true: all that matters is who won.

It is no coincidence, then, that a rise of fake facts in politics has been accompanied by a new opacity, where studies can be conducted on the impact of Brexit upon the nation, yet its citizens aren’t allowed to know what they contain; where a president can press his personal interest in a phone call with his opposite number in another country, yet not release the transcript.

The contents of all these documents are secondary to the message: it’s not your business, because we’re in charge. Far more chilling than the likely economic consequences of Brexit has been the rise of zero-sum politics; a prime minister asking her parliament to unite behind her, as if five centuries of due process, opposition, scrutiny and critical thinking had never happened.

In a new political context of authoritarianism, misogyny flourishes not as a sideshow, but because the organising principles that fought it are under attack. All equality battles are won on the understanding of universal human rights: a worldview in which everybody is born equal, everyone’s potential is infinitely precious, everyone’s perspective enriches understanding, everybody has a right to be heard.

Once all that is rejected, in favour of a worldview in which a single, dominant perspective must obliterate all others, a common understanding of equality and respect that seemed so solid suddenly appears precarious.

Arguments belonging to the middle of the last century resurface. Are women fit for public office? Are women responsible for male violence? Do women deserve reproductive autonomy, or will they just mess it up?

Of course, these arguments never truly went away. But strongman politics is back, and it sees sex and trade and debate all as wars, in which there is no possibility of mutual benefit: there is only the victor and the vanquished.