If Harry Potter had been published by Marvel Comics, he would have been called a mutant.
However, and this is not directly based on Christianity, would shy away from Harry Potter. Witchcraft and wizardry were actual things which took place here on Earth. Secret societies gathered together at night--as though they had something to hide--and performed rituals. Biblically, there are suggestions that they communed with fallen angels, and the groups do have a satanic connotation. As it is, hold a suspicious view of groups such as the freemasons, because of their penchant for ancient 'wisdom' and their secrecy--and they may be a secular group. This combination of secrecy and connection with satanic worship is what is unsettling. Personally could watch a bunch of Psychos, but would shy away from watching The Exorcist as a cat shies away from water (supposedly). Even tend to be touchy about stories which are linked (at least by some) to Christianity. LotR is a case in point. Even Narnia--which isn't nearly as dark as LotR--try to reinforce: Aslan is not Christ; Aslan is a lion who has some similarities to Christ and in some ways diverges from Christ. It is a personal thing, not necessarily a Christian thing. It isn't that Harry Potter has superpowers that is being questioned, but what is behind those superpowers.
In contrast, the Force stuff is related primarily to Eastern religions, which in a Western sense might appear to be more philosophy than religion, although the two are linked (Christianity is more closely linked to philosophy than to superstition and magic). The situation isn't nearly as sinister (opinion) as in Harry Potter, even for the Sith. And although there are similarities to Eastern religions/philosophies, the Force is not an actual thing which happened in the actual world. It does not have an ancient, darkly mysterious history--it was conjured up by George Lucas c. 1970 and has been changing since. You might disagree, but it doesn't seem quite evil. At most, it would be similar to reading The Odyssey or other stories with paganism. There's paganism, but it isn't quite as malevolent.
Anyway, that's opinion, and again, it was not an attempt to criticize Christians who read Harry Potter, just that personally would shy away from it.