A pithy portrait of the psychology involved. It really is like that for them. They are True Believers (a la Eric Hoffer's classic). Ideology is religion in the guise of politics. One has to understand that it is their faith, held with the fervor of religious fundamentalism. Like you say, it is not one or another policy, stance, or idea. It is all of one piece, one stance, one big certainty, and to let a crack of doubt open anywhere, is for their world to collapse, so that cannot, must not, be. Just one quibble: it would not feel almost as bad as backing into the car across the street, but much, much worse.