Bigotry is probably the thing I detest most. [...] I really like to explore the idea that difference is equal and good. Oppressed groups are not, generally speaking, people who stand firmly together -- no, sadly, they kind of subdivide among themselves and fight like hell. That's human nature, so that's what you see here. This world of wizards and witches, they're already ostracized, and then within themselves, they've formed a loathsome pecking order.
J. K. Rowling