It took me years around that sort to realize the common denominators: it's a fundamental lack of curiosity about the world combined with a legitimate inability to see the world through any perspective but their own.

Throw in some ill-defined fear, insecurity, and anger at their situation in life.

I think that all people and many non-person animals have dynamic and complex inner worlds, but Conservatives definitely have a blind spot when it comes to political evaluation. Unfortunately, it's our nature as our species to seek out shortcuts. One of the ways we do this is by finding trusted sources to do some level of evaluation for us, that way we don't have to think about as much. With Conservatives, many of them learned to trust certain sources from their parents, religion, or their own misguided fear. These sources are conspiratorial and hate-mongering, and they usually don't apply any critical analysis to them. This leads to a self-perpetuating cycle where their sources tell them to trust no one and to be hateful and from that they don't pick up any new sources, causing them to enter an echo chamber they can't escape. It's honestly kinda sad and I somewhat pity them, but I still will do what it takes to defeat them politically.