I always thought it was interesting that there’s precisely one instance of actual racism (as opposed to magical-world racism) in the Harry Potter books:

“Hey, Johnson, what’s with that hairstyle, anyway?” shrieked Pansy Parkinson from below. “Why would anyone want to look like they’ve got worms coming out their head?”

JKR could and should have included more since so much of Harry Potter was, well, about racism, but I find it so weird that fandom’s so pro-Pansy (and Draco, etc) after that.