Kamala Harris’s memoir, published this week, has reignited speculation that the senator has her eyes on a Presidential run. Harris – a self-made public servant with a solid record on progressive causes – should be a strong candidate for the Democratic ticket. Somehow, however, she isn’t.

The former California Attorney General’s biggest problem is that the left has changed: rather than organizing around unions or the party itself, a large chunk of the Democratic base now mobilizes around identity issues. Some of these pet causes make a lot of sense; others less so. Either way, Harris breaches two of the big ones.

First of all, she’s a career prosecutor – or as the new left like to put it, ‘a cop’. No matter that, in her 30-year career, Harris has wrestled head-on with some of the most contentious issues in America – from racial bias in the criminal justice system to capital punishment; for Harris’s opponents, who regard the whole system as beyond-redemption, she’s an unashamed agent of white supremacy. Even though she’s, well, black.

This blind hatred of police, and the criminal justice system itself, has been raging for a while amongst the hard left. Just look at the ubiquitous slogan ACAB (all cops are bastards), an old prison motif first popularized by skinhead punk bands in the Eighties, and now held up as a fashionable creed by people with expensive college degrees.

One part of Harris’s record is particularly ‘problematic’: her role in the closing down of Backpage.com, a sleazy website which had become synonymous with the street sex trade in America, before finally being seized by the FBI last year. Incredibly, the closing of Backpage has become a pet campaign for the ultra-woke left, who see it as a burning injustice which must be overturned.

Backpage, which was accused of profiting from coerced prostitution and the abuse of minors, had become a serious bête noire for federal and state authorities, ever since the site shot to popularity in the early 2000s (making millions for its owners, the Village Voice Media group). Prosecutors, including Harris, leaned heavily on Backpage’s CEO, Carl Ferror, on charges ranging from money laundering to facilitating the sale of child sex, in an attempt to close it down.

Annoyingly for Harris, the modern left has gone a bit cuckoo over sex work: rather than grappling with the serious ethical issues involved, a league of postmodernist fantasists has reinvented prostitution as purely an issue of individual choice – and sex workers themselves as an identity group on par with racial or sexual minorities.

That’s why left wing opinion is already moving against Harris. On Twitter – where the woke left distills its tribal identity – the memes have started: ‘Kamala Harris is a cop’, they say. Others accuse her of ‘persecuting’ sex workers through her work on stopping Backpage (which, whatever your position on sex work, was almost certainly operating in breach of federal law).

It will only get worse: the hardening of the American left now means that a growing number of activists are willing to forgive nothing in their struggle for ideological purity. Good news for, say, Bernie Sanders (who forged a Congressional career on opposing things, rather than ever getting his hands dirty) or newcomers without baggage (like Alexandria Ocasio-Cortez, should she run in 2024). Bad news for anyone like Harris, or Cory Booker, involved in grown-up politics.