This week we celebrate the 20th anniversary of the first Harry Potter novel, and the beginning - in Britain, at least; the first volume's publication in America came a little later - of a cultural juggernaut that defined a generation's experience with books.
It is a timely anniversary, since if you believe what you read on social media, the Potterverse has never been more relevant. As Western politics has become more extreme and a generation raised on Hogwarts more politically engaged, the Potter novels have been embraced ever more fervently as political allegories and moral manuals for our times.
As I write this, The Telegraph of London has just informed its readers that a poll reveals that Mr Jeremy Corbyn belongs in Gryffindor while Mrs Theresa May should be in Slytherin - respectively the bravest and most sinister of houses on the Hogwarts campus. Mrs Hillary Clinton has just given a speech praising the Potter novels for instilling progressive values in the young. Meanwhile, the social media celebrations of 20 years of Potter have temporarily crowded out the endless liberal memes comparing Mr Donald Trump and his court to Voldemort and his Death Eater lackeys.
Writing for The Spectator recently, Ms Lara Prendergast offered a good survey of the proliferation of Potterpolitics, from anti-Trump organisers invoking "Dumbledore's Army" to author J. K. Rowling's Twitter interventions ("Voldemort was nowhere near as bad," she wrote of Mr Trump's proposed Muslim ban) to Hermione Granger's - sorry, actress Emma Watson's - role as an ambassador for millennial feminism.
Ms Prendergast also offered a harsh assessment of the trend: "If you have ever wondered why young people are often so childish in their politics, why they want to divide the world between tolerant progressives and wicked reactionaries, it helps to understand" that they think they're living in a Potter novel.
Admittedly, if you think that the world really is divided between tolerant progressives and wicked reactionaries, you won't find this assessment all that damning.
But I'm not sure that sort of Manichaean vision is actually the most important political teaching in the Potter novels. Because if you take the Potterverse seriously as an allegory for ours, the most noteworthy divide isn't between the good multicultural wizards and the bad racist ones. It's between all the wizards, good and bad, and everybody else - the Muggles.
For the six readers who have never read the Potter books but who have stuck with the column thus far nonetheless: Muggles are non-magical folks, the billions of regular everyday human beings who live and work in blissful ignorance that the wizarding world exists. The only exception comes when one of them marries a wizard or has the genetic luck to give birth to a magic-capable child, in which case they get to watch their offspring ascend to one of the wizarding academies while they experience its raptures and revelations second-hand.
The proper treatment of Muggles, meanwhile, is the great controversy within the wizarding world, where the good guys want them protected, left alone and sometimes studied, while the bad guys want to see them subjugated or enslaved (and all the Muggle-born "mudbloods" purged from the wizarding ranks).
All of this plays as an allegory for racism, up to a point… but only up to a point, because what's notable is that nobody actually wants to see the mass of Muggles (as opposed to their occasional wizardish offspring) integrated into the wizarding society. Indeed, according to the rules of Rowling's universe, that seems to be impossible. You're either born with magic or you aren't, and if you aren't there's really not any obvious place for you in Hogwarts or any other wizarding establishment.
So even from the perspective of the enlightened, progressive wizarding faction, then, Muggles are basically just a vast surplus population that occasionally produces the new blood that wizarding needs to avoid becoming just a society of snobbish old-money inbred Draco Malfoys. And if that were to change, if any old Muggle could suddenly be trained in magic, the whole thrill of Harry Potter's acceptance at Hogwarts would lose its narrative frisson, its admission-to-the-inner-circle thrill.
Which makes the thrill of becoming a magical initiate in the Potterverse remarkably similar to the thrill of being chosen by the modern meritocracy, plucked from the ordinary ranks of life and ushered into gothic halls and exclusive classrooms, where you will be sorted - though not by a magic hat, admittedly - according to your talents and your just deserts.
I am stealing this magic-and-meritocracy parallel from the pseudonymous blogger Spotted Toad, who wrote a fine post discussing how much the Potter novels and movies trade upon the powerful loyalty that their readers feel, or feel that they should feel, towards their teachers and their schools. But not just any school - not some suburban John Hughes-style high school or generic Podunk U. No, it's loyalty to a selective school, with an antique pedigree but a modern claim to excellence, an exclusive admissions process but a pleasingly multicultural student body. A school where everybody knows that they belong, because they can do the necessary magic and ordinary Muggles can't.
Thus the Potterverse, as Toad writes, is about "the legitimacy of authority that comes from schools" - Ivy League schools, elite schools, US News & World Report top 100 schools. And because "contemporary liberalism is the ideology of imperial academia, funnelled through media and non-profits and governmental agencies but responsible ultimately only to itself", a story about a wizarding academy is the perfect fantasy story for the liberal meritocracy to tell about itself.
Especially because (unlike reality) it writes the Muggles, the genuinely ordinary people, out of its political clashes and good-versus-evil conflicts. In the Potter novels, the selective school is conterminous with wizarding society as a whole (allowing for some elves and goblins to do maintenance and keep the books), and thus the threats to that world's liberal integrity all come from within the academy's walls, from Slytherin House and its arrogant aristocrats, who must be constantly confronted in the halls and classrooms of the beloved school itself.
Voldemort, the dark lord, has Muggle blood, but he isn't trying to rally an army of non-magic-wielders to seize Hogwarts' towers; he's trying to remake meritocratic - er, magical - institutions in his own dark image. And so the battle for Harvard - er, Hogwarts - is the battle for the world.
Which is basically the premise of a great deal of youthful liberal activism these days - that once the last remnants of Slytherin are eradicated from the leafy quads of Yale or Middlebury, once Draco Malfoy's frat or final club is closed and the last Death-Eater sympathisers purged from the faculty, then the battle of ideas will have been finally and fully won.
But even if it were, beyond the walls of the imperial academy all of our world's Muggles would still remain, with an agency and a power that they don't have in the Potterverse.
Because after all it was mostly Muggles, not some dark conspiracy by the Slytherin sort of conservatives, who put Mr Donald Trump in power.
It is Muggles who keep turning to parties of the far left and farther right, Muggles who drift into radicalism and set off bombs. Mass migration, rising nationalism, Islamic terrorism, rural despair - many disruptive forces in our era flow from global Muggledom's refusal to just be a tame and subsidised surplus population, culled for its best and brightest, living only for the hope that occasionally a gifted son or daughter might be lifted up.
In the Potterverse, the meritocracy of magic allows the chosen to withdraw, to disappear behind a curtain into their academic world, leaving Muggledom to its own devices.
In our universe, though, the meritocracy of talent expects the chosen to actually go out and try to rule. On the evidence we have, they are not particularly good at it. And how to lead wisely in a society where most people did not go to Hogwarts is a lesson that J. K. Rowling's lovely, lively, but ultimately childish novels do not teach.