2. Harry even raises and trains a private militia (Dumbledore’s Army), without the government’s knowledge or approval, to fight off bad guys the state is incapable of protecting him from. That militia then fights a major battle, with privately owned weapons, to successfully defend their castle from enemy invaders. What could be more libertarian than that?
3. The government in the story – the Ministry of Magic – is fighting against Harry the whole way. State run newspapers slander him. Attendance at school is made compulsory as a misguided and unpopular attempt to keep track of the kids. Azkaban is an oppressive state prison with horrible conditions and regular torture, in which not all the prisoners are bad guys who deserve to be there. The government is inept at best, and infiltrated with corrupt death eaters at worst. When Harry tries to spread a startling truth (Voldemort’s return) which runs contrary to government interests, he is silenced and ridiculed and made to appear crazy by the state run press. When a private school (Hogwarts) is found to be conducting its business in a way the government doesn’t like, the government creates a “Hogwarts High Inquistor” position to meddle with their affairs and ensure they toe the line. All the government characters are presented in a negative light; Cornelius Fudge as a bumbling fool, Dolores Umbridge as a dishonest and infuriatingly authoritarian busybody, and Percy Weasley as a naïve sucker who buys into it all.
4. The protagonists are liberal on all the social issues. The muggle/wizard dichotomy is a clear microcosm for racism, with lots of analogies to Nazi Germany thanks to the “pureblood” rhetoric of the despised Malfoy family and Slytherin House. The reader sees how ridiculous this is throughout, however, since the smartest and most competent of them all is Hemionie, who is mixed blood. Speaking of Hermione, she is also a trailblazer for women’s rights, who encounters and overcomes sexist putdowns at every turn. Arguably the most beloved character, Dumbledore, is homosexual. Werewolf infection is treated similarly to HIV infection, or even leprosy, in that we are made to sympathize with the social castigation it causes. The reader also sympathizes with the enslaved House Elves, and Hermionie’s relentless social advocacy for their rights reinforces the themes of liberty, diversity, tolerance, and empathy which drive the leftist half of libertarian thought. The series is also anti-torture and anti-death penalty: only the bad guys use the crucio or avada kedavra spells. Harry himself only kills Voldemort in self-defense by deflecting his own spell against him. You could even argue it’s anti-war by illustrating the pain of losing friends in a major battle.
It's been a while since I've read the books, so maybe my readers will recall even more libertarian details. In any case, the Harry Potter series was one of my favorites growing up, so I'm pleased it's had such an influence on the moral outlooks of my generation.