Perhaps not the greatest threat, but certainly a very serious one. Frankly, the entire right-wing religious position, with all its ramifications, could easily qualify as the greatest threat. That is, it's all the same people.
I've been reading a book about Blackwater, and before that one on authoritarian education, and before that the shadow group called "The Family" that runs the C Street house and much of the back-room dealing in Washington. And before that . . . but you get the idea.
