Re: "Stormy, you're a fine girl..."
Obviously we're dealing with archetypes here, and real people aren't that clean-cut, but I think you get your first clue when someone consistently chooses belief over blatant reality.
The man you're talking about is perfectly normal. But he would have become a problem if he decided he could shield people from a reactor core's radiation solely by painting crosses on the steel walls.
We are dealing with political beliefs right now that almost fall into that category. That's what scares the crap out of me. I hope to God you're right that the problem here is that I'm a crappy debater who's no good at convincing people of anything.