This is a continuing urban legend. Up north, in the Panhandle Area the Arian Nation people use to hang out and the media made a huge deal of them and their "marches". Fact is, there were only about a hundred of them at their site with maybe fifty showing up at their events.
Now they have left the state for good and went down south to Alabama or some such.
Most people in rural Idaho, by far the vast majority, are red-blooded, religious and conservative Americans who support and defend the constituion. And I speak as one living in rural Idaho outside of BOise.
They were out there in the PAC NW before the Mormons got to Utah!
This is the gang that doesn't use doctors. Most of their members have gaps where other folks have teeth since they don't go to dentists either.