I was friends for awhile with a woman who was almost the total opposite of me in terms of opinions on various controversial topics. We had plenty of other stuff in common, though, so we enjoyed spending time with each other. She had always been rather passionate about her stance on various controversial topics and once in awhile, she would voice those opinions. But I would respond very neutrally.
And that worked out fine for quite a long time. Until she started going off the rails. She kind of went nuts over her favorite controversial topics and would start to scream and yell at myself and other mutual friends about these topics. None of us really wanted to get into a huge debate with her. She wouldn't let up. She started loudly vocalizing opinions along the lines of "If you don't agree with me on __, then you are _insert-a-negative-label-here!"
What did in the friendship finally for me was when she started text bombing me at 10:30 pm demanding that I answer to and explain some controversial person's supposed position on Controversial Topic X of the moment. I blocked her # from then on and didn't really talk to her again after that. I got tired of being yelled at and called names. I got tired of her jumping to conclusions and refusing to even have a calm adult conversation about Controversial Topic Of The Day. She had almost lost her mind about it all. Through her behavior and actions, she had demonstrated to myself and many others that she, herself, was, in fact, the names that she tried to label the rest of us with. It was the straw that broke the camel's back. She was relentless on HER 'important topics.' The amount of prejudice from her was totally and completely over the top and kind of insane.
Looking back on it, however, I do think that she was likely dealing with a lot of mental health issues at the time and probably needed to be on some medication. She had a lot of other drama going on in another part of her life and instead of seeking counseling to help cope with that stuff, her stress manifested itself in this way instead. She would read nuances into things you'd say to her that weren't really there.