I'm not saying that I agree with him at all, but I think it's important to understand this kind of behavior, rather than merely dismissing it as a crazy person. Though it is quite possible he is crazy, too.

But I think he feels like his political beliefs are being dismissed by others because they are controversial. There's a certain kind of person who's really attracted to contrarian beliefs like that. He thinks he can provide rational arguments for their beliefs, but people dismiss him and downvote him anyway.

This probably led to t̶h̶e̶ ̶s̶o̶c̶k̶p̶u̶p̶p̶e̶t̶ ̶a̶c̶c̶o̶u̶n̶t̶s̶ ̶t̶o̶ downvote people he didn't like [and sockpuppet accounts to upvote his own comments to undo it]. Again, not defending this at all, just trying to understand it.

Many people treat downvotes like insults. If your comment gets downvoted, its kind like if a bunch of people told you loudly and publicly "Shut up!", or that you are stupid. It's a public humiliation and a loss of status. That can lead to anger and frustration and a desire to get revenge.

Downvotes as shaming is a real effect. I certainly don't post comments which I think have a chance of being downvoted. Which is why I post comments here much less frequently than I otherwise would on other discussion sites. And I'm not trying to complain, because I love reddit's comment system and think it's really good at filtering discussion. But it is problematic that people treat it like a disagree button.

Then he gets banned for that behavior. That feeds into his persecution complex and gets him even angrier. And well, we've seen the results of that.