The documentary Britain’s Strictest Headmistress hit the small screen on Sunday. It continues to do the diligent work of Katharine Birbalsingh, in mythologising herself so furiously that, if you didn’t have a memory or know any better, you would think she invented the phrases “please” and “thank you”.

Birbalsingh is not a bad figurehead for the age we are living through, that of asymmetric polarisation. She can come out with any idea she likes – girls don’t like maths or liberals don’t like Shakespeare – but express any hint of dissent, ask even the mildest question about the evidence base, and you might be referred to by her defenders as the hysterical mob. It’s generally safer to just leave her be, which is fine, because more interesting than her didactic method is the response to it from rightwing commentary.

The consensus in this camp is that Birbalsingh has done something incredibly unusual, magical even, in creating a safe learning environment. And yet this wouldn’t fly without an audience that had never set foot inside any other state school.

I went to a private school myself, so I can track the logic precisely. They start with the premise that private education must be better, since how else could you explain the superior results, university places and jobs? They set this against their own experience of private school, which was probably mixed – some good teachers, some bad, and quite a bit of bullying – and they proceed to the conclusion that state schools must be much worse: “thicker” kids, worse behaviour and a total lack of aspiration. Sprinkle on a bit of half-remembered Grange Hill, and wham – regular state schools are the wild west and Katharine Birbalsingh is Clint Eastwood.

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