During WWII the United States government rounded up tens of thousands of people, including many US citizens, and put them in internment camps because they looked sort of similar to the people who bombed pearl harbor. Why? Because fear is a powerful drug and when people are afraid, logic tends to go out the window, if there was any logic to begin with. If you pay attention to conservative rhetoric, you'll notice that much of it is intended to stoke fear, while inserting themselves as the solution. They do it because it works.
Way out in the Arkansas Delta, in a soybean field 50 miles from anywhere, there is a memorial where one of these internment camps stood. If you aren't looking for it, you'd probably drive right by it unnoticed. All around the camp there are these little voice boxes that you push a button on and it explains what you're looking at. The voice providing the narration is none other than George Takei who was held there with his family as a child.
Spend a little time at a place like this and it will quickly disabuse you of the notion that America has always rejected fanaticism.