That's because leftists don't allow civil discussion. If you don't agree 100% with their view you are a Nazi, homophobe, xenophobe, misogynist, etc. They even eat their own who stray from the narrative.
That rule applies to Facebook/Tumblr echo-chambered leftists. It doesn't help when someone is trying to be reasonable and the person being debated with comes out with a half-assed "you're a triggered libtard" response.
what liberals here scream racist, Nazi, or homophobe.
it is more often that the right is screaming triggered snowflake.
ruthlessly making fun of liberals over and over is just how you guys have fun, its not a response to the left at all
I'm of the opinion that this is one of the last internet bastions for repubs and/or free speech in general.. but I could be wrong. Sometimes I wonder if some of these people are even American. Sewing American discord seems a logical possible agenda.