conservatives are stupid brainwashed
Fixed it for you. While they certainly have more than their fair share of absolute dunces too, they don't believe in nonsensical things because of a lack of intelligence.
Most of them have been subjected to literally the same kind of programming that (other) cults use to ensure obedience and coherence for their entire lives, and then turned up to 11 for the past decade or so.
It's not about being stupid. It's about being successfully duped.
Disclaimer: I'm not pointing this out to absolve them from the consequences of their words and actions.
I'm pointing it out because you can't defeat indoctrination by just assuming that the cult members are just morons who can't know better or ignorant people who haven't been told the objective truth.