No one in the public eye should expect to avoid scrutiny and criticism. As the UK’s first black female MP, Diane Abbott never had the opportunity to be so naive. She has not only weathered political storms and prejudice but endured years of outright abuse without complaint. Now, as she has revealed in the Guardian, things are getting worse – and it is preventing people from entering the field or speaking out: “Once, the pushback was against the actual arguments for equality and social justice. Now the pushback is the politics of personal destruction,” she wrote.

That reflects in part a political discourse that is becoming coarser and more vicious. But those who do not fit the traditional mould of a public figure – white, male and straight – are more often subjected to vitriol, and such vitriol will more often focus on their identity, not their opinions. These attacks are not only ad hominem. They are in many cases ad feminam, or, as in Ms Abbott’s case, doubly poisonous, driven by racism and sexism.

It should be extraordinary that high-profile women receive a torrent of hate messages directed at their gender and ethnicity, and rape and death threats. Instead, it is becoming routine. Female MPs say they feel physically unsafe; Jo Cox was targeted online before her murder by a far-right terrorist, and her death is used to threaten them. Other women who dare to speak out are similarly abused, as Gina Miller and Caroline Criado-Perez could attest. Social media has amplified longstanding prejudice, increasing the pressure on its targets through volume and normalising personalised abuse and hatred.

Some see in the hatred a backlash against the mistaken pursuit of identity politics by progressives, who have narrowly focused upon the interests of racial, religious and sexual minorities and women. This is wrong on many counts. It treats equality as a niche interest for those who have not obtained it rather than a broad ideal; it suggests that campaigners for, say, sexual or religious rights show no interest in economic wrongs or other issues; it regards one group’s priorities as universal and others as myopic. More pertinent is the erosion of community ties and an economic system that induces a sense of perpetual competition for survival instead of cooperation, creating anxieties easily exploited by the unscrupulous.

Female politicians around the world have found that the closer they come to power, the more determined people are to silence them, often by humiliation or intimidation. What is striking is that the hatred is directed not even at equality, still so distant in so many regards – not least political representation and economic inequality – but at gradual advances made towards it. Such attitudes may seem marginal, but breed when they are not confronted. Donald Trump’s election and his administration are emblematic of the way that previously extreme arguments and perspectives are entering the mainstream. In the UK, many forces drove the Brexit vote, but the increase in hate crimes afterwards suggests some took it as a licence for their worst instincts. Even those horrified at the explicitly racist or sexist bile directed at Ms Abbott and others may find their own perceptions tainted by more insidious attacks.

Reversing this current will be slow and demanding. Our leaders need to make it clear that there is no place for misogyny and racism in public life. Technology firms must get as serious about tackling abuse as they are about, for example, copyright infringement. Other institutions too must consider how they handle the problem. Finally, the rest of us should challenge prejudice, resist the normalisation of cruelty and bigotry, and consider how we can build a civil, inclusive and constructive public sphere. Freedom of speech is precious. But it is not an inalienable right to bully, threaten and belittle others into silence without consequence. It is, in part, about creating and maintaining the conditions in which the widest range of people can find and use their voices.