So your brain can handle tiny wizards running through walls but not a black Hermione? Sure, that makes sense

Nowadays, we get told a lot of things are racist - yoga, the Village People, 'Mexican Mondays' at Wetherspoons - but this time round, I really am inclined to agree with J K Rowling that people who can't get on board with a black actor playing Hermione are a bunch of racists

Noma Dumezweni plays author JK Rowling's character Hermione Granger in a stage adaptation of her works (Getty)

“With my experience of social media,” said JK Rowing, discussing the casting of Swaziland-born, Olivier award winning actress Noma Dumezweni in the stage role of Hermione Granger, “I thought that idiots were going to idiot. But what can you say? That's the way the world is. Noma was chosen because she was the best actress for the job.”

Rowling went on to describe critics of the choice as “a bunch of racists”. She is, to my mind, completely right, and her devil-may-care attitude to causing a social media rumpus is relentlessly pleasing.

On Twitter, Rowling is forthright on Scottish politics, sporting loyalties and her regrets over Harry Potter plots. She speaks without fetter, riding each ensuing 72 hours of rapey backwash and bile from mum’s box bedroom with a steely, nay, raffish veneer.

In the case of ‘Harry Potter and the upsettingly non-Caucasian Hermione’, Rowling is perfectly right to deem those moaning as racist. It’s pure, Category A, slack-jawed beginners level, I-Spy ‘Big Book of old-school Racism’. It’s up there with ‘Why can’t I sell grinning gollies in my regional gift shop?’ and ‘Chelsea fans helping with Paris Metro overcrowding’.

Whining and claiming your special thing will be 'spoiled' and threatening to boycott a film or play due to the inclusion of a brown-skinned person is reminiscent of Alf Garnett coughing up derisory phlegm behind his newspaper.

Your brain was willing to relish tiny wizards running headlong through a wall at a busy London commuter station, and being transported to a magical world of curses, ghouls and broom-riding contact sports. But brown people? No, no, no – it’s just a bit far-fetched.

Floating the notion of Idris Elba as the next potential James Bond has an equally toxic effect. It’s like leaving a jam sandwich out in hot weather and waiting for an ant-hill. All racists will re-route there, claiming their interests are patently due to dramatic authenticity.

The dilemma with naming and challenging rock solid cases of racism – just as Rowling is – is that we live in an era where the r-word has lost its punch.

Over the past six months I’ve heard that ‘Mexican Monday’ at Wetherspoon is borderline racist and being punched by Jeremy Clarkson is racist too. Doing yoga in a community centre while not being a genuine Hindu Upanishad is racism and singing Shaddupya Face by Joe Dolce is essentially a racist act.

Being Andy Murray’s girlfriend and muttering something sweary at his Czech opponent? Racist. Enjoying the work of 1970s Disco sensations Village People without first checking if Filipe Rose had the cultural background to dress as a Native American? Racist.

What about claiming any of the above aren’t really racist? Well, that’s the most racist thing of all.

Trying to weed out true racism from petty grievance in the modern age often reminds me of the stoning scene in Life of Brian. “I only said to my wife,” explains the supposed blasphemer, “This piece of Halibut was good enough for Jehovah”. But there’s no time for nuance or explanation before the patently gleeful lobbing of stones.

If this makes claims of racism soporofic at times, then the response to Noma Dumezweni as Hermione, or Idris Elba as 007, should act as a jarring prod.

Rejecting Noma Dumezweni suggests that it is beyond your human reckoning that there are many young, clever women of colour attending British public schools. It also suggests that you see a brown woman in this role, rather than as “a casting decision based on merit” but instead as part of a PC agenda you refuse to stomach.

It suggests an inability to simply forget what colour people on stage or screen are, and instead sit fuming each time they appear because someone with ‘better’ skin should be playing the role. It suggests that, even when you’ve paid hard cash to be immersed and intoxicated by the joy of drama and you’re sitting on a velour-covered seat, clutching your programme, you refuse to leave your prejudice in the foyer because it’s seeped into every nook and cranny of your blood, guts and bones.

JK Rowling is right. That’s racism. The show will go on without you.