I didn't say it was ALL Trump's fault, but he has changed the discourse. People have a misconception of what "PC" is, but certainly many have expressed that Trump has freed them up to say what they really feel, whether it's about women, race, immigrants, et al.
I don't think it's really too disputable that the childish, insulting nature of his near-constant tweeting has had an effect. If you don't see POTUS as setting any kind of example in that regard, we'll really just have to disagree on that.
95% negative coverage by media, much of it misleading, or flat out fabrication. THATS what has changed our discourse.