But in fact many political zealots never accept reality. It's not just that they're inherently skeptical of what the other party says. It's that even when something is proven beyond a shadow of a doubt, they still won't believe it.
This could describe cognitive error [1] or it could describe someone who's using deontological reasoning more than consequentialist reasoning. (And perhaps lacking the vocabulary to say "consequentialist arguments won't sway my values.")
It is probably a good strategy to refuse to be talked into positions against your fundamental values by mere evidence. I'm joking but also serious. I have a vague sense that torturing suspects doesn't work to prevent terrorist attacks, but that's not the root of my opposition to torture. Maybe clever torturers could make it work more often than not. That wouldn't sway me, because torturing suspects is against my values. Documenting how well it can "work" won't make me reconsider.
[1] Further food for thought: "cognitive error" and "revealed preference" may also be different names for the same thing. Are they experimentally distinguishable?