I strongly suspect the things people believe in are usually just what they instinctively feel is right; the excuses, the justifications, the things you’re supposed to argue about, come later. They’re the least important part if belief. That’s why you can destroy them, win an argument, prove the other person wrong, and they still believe what they did in the first place.
Iain M Banks Use of Weapons
Well, not actually Iain, and not about immigration, but you get the idea.