I once knew a guy who trolled a high quality policy discussion forum. His beef was that his wife made him go to a church that had a bunch of liberals, who would

I once knew a guy who trolled a high quality policy discussion forum. His beef was that his wife made him go to a church that had a bunch of liberals, who would regularly say stuff that would enrage him, but which he couldn't respond to. The only thing that made him feel better was to piss on liberals online. So one possible explanation is that some of these people feel frustrated and angry because for whatever reason, they're not able to voice their own political opinions in real life, so they get a rush from the power of denying random people on the internet that same freedom.