Seeing as the way the fundies in USA understand "freedom of religion goes a bit like this:
"You see, the laws say "freedom of religion" not "freedom from religion" and it means that religion is protected from the government, that is why you goddamn atheists can't prevent good Christians from practicing their religion."
...To explain this bullshit they are going to have to claim that Islam isn't a religion and that only Christianity counts as a religion, or something like that.