Blogging at NPR, Tom Regan asks the essential question:
So now I've read all the books and seen all the films made so far. And the best things about these books are what they teach children -- and, it must be said, adults -- about what's important in life: family, loyalty, friendship and love. (This is why I think it's a mistake to ban Potter books for their "magic.") But most of all, it may be about the choices that we make, and how they determine who we really are, despite what we say or think.I've written before that I believe it is a mistake to characterize the fundamentalist world view as a strict dichotomy between Good and Evil. Regan makes a similar mistake is assuming that, in the fundamentalist mind, the moral worth of someone's actions have anything to do with the actual content of the action. It is not Good vs. Evil, it is Us vs. Them. Fruits such as those Regan lists can only be legitimately achieved by first swearing allegiance to their particular brand of Christianity; any other method must be shady and somehow deceptive. This is most explicitly stated in this clip from Jesus Camp, posted by Orcinus.
This twisted polarization comes, I think, from a logical extension of the Calvinist idea of total depravity, or even the wider notion of "salvation by works," an important cog in the Protestant Reformation. This is the notion that, no matter how much good a person does, it will never be good enough to earn a passage into Heaven; that can only be achieved by acceding to the will of God (which Calvinists will argue up and down does not somehow qualify as a willed action, which I don't find compelling but that's a long subject for another day.)
But the good Calvinists are being deliciously betrayed here by their more zealous brethren, who have gone to the natural conclusion of asserting that therefore any good deed attempted under the auspice of another belief system is hollow and worthless and likely a trick of the Devil.
There is another reason why the fundamentalists have so much antipathy toward Potter, brought up in Orcinus comments by Dread Scott.
Most people have a functioning ability to distinguish between fantasy and reality and see the Potter series as good entertainment. When people are raised to reject rational inquiry as immoral and instead devote themselves to superstition and mythology, works of fiction can be perceived in a way as competing faiths. While most adult fundies aren't going to be waving wands and trying to ride broomsticks, they see the Potter series as a threat to the proper indoctrination of children who might get confused about which fantasies to believe, especially if another is more appealing. Or, at least that seems to be what they fear.
Indeed, if one has much cohabitation with the fundies, their complaints generally will progress along these lines. Fundamentalism is commonly characterized by an absence of real faith, and the adults deeply realize that they are beholden to beliefs that seem fantastical and incredulous. It greatly concerns them, then, that their less well-adapted children will see a competing fantastical, incredulous belief system, even in a book that obviously fiction. And indeed, fundamentalists doubt the very existence of fiction, since they deeply suspect they are following fiction themselves.