When a clever woman threatens a man who demands submissiveness, he can suggest that she’s only interested in screwing him. If that doesn’t work, he can silence her by threatening to rape her or by sneering that she’s not worth raping, anyway. And, when the woman protests, he can smirk and say, “Can’t you take a joke, love?”

I’m only trying to “normalise comedy”, explained Ukip’s Carl Benjamin after he told Labour’s Jess Phillips, “I wouldn’t even rape you” and added: “I suppose with enough pressure I might cave, but let’s be honest nobody’s got that much beer.” The famous British sense of humour, which intrigues so many foreigners, will doubtless have left tears of mirth streaming down your cheeks.

While you mop them away, consider that the jokers don’t confine their pranks to our borders. A YouTube channel, run by an anonymous German rightwinger, discussed the “dumbness” of the Bavarian Green politician Katharina Schulze. “OK guys, hand on your hearts and be honest: Katharina Schulze, would bang? Yes or no?” reads the first comment. “Noooooooo. Rather burn her,” comes the first reply, followed by others I can’t print but that YouTube was happy to publish. In Catalonia, the liberal leader Inés Arrimadas is treated as if she is an impurity whose stain must be removed. Separatists cleaned a pavement she had stepped on yelling, “let’s disinfect” after she visited a Catalan town. The courts jailed a (female) opponent after she called for Arrimadas to be gang raped for opposing Catalan nationalism.

Many still laugh along. Even after a far-right terrorist murdered Jo Cox, the “alt-right” mouthpiece Breitbart kept the joke running and the show on the road by insisting he wasn’t an ideologically motivated terrorist, as a Muslim killer would have been, but just “a deranged loner”.

A report from the ISD anti-extremism thinktank, which will be released after the European elections, shows how far-right and ultra-nationalist movements are conducting their version of the old left’s “long march through the institutions” and undermining democratic culture as they go.

Ukip’s Carl Benjamin is confronted by a protester in Weymouth, Dorset on 17 May. Photograph: Tom Corban/REX/Shutterstock

It begins with trolling. And if you can’t take the “comedy”, what kind of frigid killjoy are you? Then they say, as Nigel Farage is saying, that broadcasters ask hard questions because they are “biased”, rather than because it’s their job to ask and the politician’s job to answer. They move on to blacken all outside sources of information that might frustrate their ambitions: not just the media, but the judiciary, parliament and the civil service. On their way, they intimidate political opponents, particularly women.

Why concentrate on the far right? When I told Stella Creasy I was writing about far-right misogyny she all but snorted. “Far right? What about the far left?” Diminishing women, presiding over political movements where the women make tea and the men decide strategy, is hardly a vice confined to one corner of the political playground. Earlier this month, an SNP MP cross-examined Twitter executives about why they published a video from a US gamer called Sonic Fox entitled “What I do to terfs”. It featured a male character cutting a woman’s throat. As you will have guessed, Sonic Fox may display the women hatred of the far right but is from the feminist-baiting left.

In journalism, I’ve seen male, black and Jewish writers abused – as a “Cohen” I receive a bit myself – but it is as nothing against the hatred my female colleagues receive. Which only proves there is a special relish that overcomes men (and many women) when the chance comes to humiliate a woman, particularly if she is brighter and more successful than they will ever be.

One remedy for involuntary celibacy (the frustrated state of incelhood) is for a man to brush his hair, lose weight and try talking to women – or, and I accept this is a radical proposal, listening to them.

Phillips gives the most practical reason for looking rightwards. She suspects that if a man goes for her, he will be a far rightist. The far left and the far right fear her because she is a politician who can cut through and challenge them both. But only the far right has a track record of violence and only the far right has misogyny at its core.

Male anxiety and male stupidity drive it. Stupidity, because this is a movement that calls its enemies “cucks”, as if its members were Casanovas climbing through bedroom windows to sleep with their opponents’ wives, and then admits to being filled with “incels” no woman will go near. One response to involuntary celibacy (the frustrated state of incelhood) is for a man to brush his hair, lose weight and try talking to women – or, and I accept this is a radical proposal, listening to them. The second is to complain that they are the victims of feminism and to hate women, particularly smart and popular women who dedicate their time in public life to protecting their sisters from those who would abuse them.

Sexual tension also powers anti-immigrant sentiment and not only because of fear of Asian grooming gangs. The “great replacement” and “white genocide” are the slogans of the conspiracy theories that hold that the EU, George Soros or the Jews want to flood Europe with Muslim immigrants and destroy white, Christian culture. They are not just the fringe fantasies of terrorists and supremacists. They fill the propaganda from Viktor Orbán’s Hungarian government. Alongside the racism is the fear that European men are not virile enough; that they are not persuading enough independent-minded women to be with them and bear their children. Once again, the public faces of women’s emancipation are the target for hatred and worse.

It is our duty to stand with them. Liberal defences of free speech always exclude incitements to violence. If the law states that Carl Benjamin and men like him cannot be prosecuted, and that Twitter and YouTube can allow hundreds of men to discuss raping a politician with impunity, then we will have to change it.

• Nick Cohen is an Observer columnist