The stupid/evil division is a real one. The idea that you find on the left, that left wing people are ex officio good people, and that right wing people are somehow morally deficient, is a self-flattering story that left wing people tell each other. Sometimes they say their problem is that they're too kind and empathetic.
There's a minor example upthread where posters are mocking Megyn Kelly for her broadcasting on CK's death, her "theatrical crying" etc. That's a woman being policed for her response to her friend's murder by people who no doubt regard themselves as kind and empathic - because MK is a woman on the right, so by definition she doesn't have any feelings.
All of us, from different backgrounds or tribes or demographics, tell ourselves stories that make us feel good. Often they're harmless. Sometimes they become harmful, because they're false or they blind us to our faults or they dehumanise those outside the tribe.
My impression is that the left does this more than the right, maybe that's the people I know, maybe reasons speculated on above are relevant. Leaving aside murder - I know this is a small thing, but when a political figure dies a natural death, and I see people on Facebook gloating over it before the body is cold, almost invariably it will be a figure on the right (not necessarily far right, could as easily be centre right) and the people doing the gloating will be left wing people who believe themselves to be kind and empathetic and morally good, and definitely not childish and creepy.
I'm not saying right wingers never do that, but you'd have to be talking about someone like Fidel Castro, and even then they don't make a whole spectacle about how happy they are.
These people on the left really do think that they belong to the community of the righteous, and they get to judge everyone else, including whether they deserve to live or die. But, seen with the distance of exile, that community looks more like The Crucible.