I also wanted to comment on the idea that polygamous communities wouldn't have to exist in isolation if polygamy was legal. Again, I've only read one book on the subject, but it was pretty clear that the leaders of the fundamentalist communities want to keep their followers isolated so they aren't exposed to "outside ideas". They aren't allowed to watch television, read magazines, go to public schools, etc. Well, I take that back -- many of the kids do go to a "public school", but all the teachers are fundamentalists, as are all the members of the school board, so anything they learn is pre-screened.