If you haven't seen violence being called then I suspect you may not be paying attention to national media (not necessarily a bad thing). The President himself has called for violence numerous times at campaign rallies and against political rivals. There's been numerous shootings at churches, clubs, synagogues, schools, etc. that inflict real violence on people. You literally have to not pay attention to not see that politics has become radicalized. Whether things like the movement that inspired President Trump and his reverents or they are merely a symptom is debatable. The fact that /r/The_Donald still exists after the numerous brigading episodes, doxxing, and malice they've brought the platform speaks widely to the latitude that they've been given. I'm generally supportive of free speech, even speech I disagree with but The_Donald censors a ton of speech they disagree with and they aren't even really being heavily punished here.