I've come across three posts, one on Jerry Falwell, one on Mel Gibson, and one on James Dobson, all prominent religious whackos in the US (Wikipedia on Jerry Falwell, Mel Gibson (mostly on his film career, but does discuss his religious weirdness) and Dobson. I'm not sure I buy the semi-psychological analysis -- it's a bit too pat, usually, to put the responsibility for a twisted mind on just one influence -- but the description of their behaviour is revealing of at least one thing: these guys don't just think nuance is wrong (as in mistaken); they actually despise it. It's like a visceral reaction: they have their simple, black-and-white rules, and anything that doesn't fit into that worldview is beyond the pale and must be ignored, rejected or destroyed. Even if that's children and small animals. While I know that sensible religious people don't think like that, certainly the vocal representatives of religious belief in the US all seem to fit this pattern. As, for that matter, do the necons. You're with Israel, or you're with Hezbollah. You're with the US, or you're with the terrorists. You're against abortion, or you like killing babies. No nuance, all extremes, and anything that doesn't fit these rubrics is to be hated, reviled, and destroyed.
The trick, of course, is how you can deal with fully-grown adults who exhibit this sort of behaviour. (Beyond institutionalizing them, I mean.) Sane people know that reality demands nuance and adaptability. If you can't face things that don't fit into your current understanding of the world, then you're going to spend a lot of time being very upset. (Which would explain why everyone on Fox News seems so angry.) So, we're dealing with people who are, to some extent, insane, or at least highly irrational.
Unfortunately, I don't have any idea how to deal with the irrational beyond being equally irrational right back. Rational means only work with rational people; so, by contrapositing, irrational people must be dealt with through irrational means. Which is an unhappy result, to say the least.