I can see why people are protesting against Trump, they are scared he will do what he said he would do. I am sure some of them get into it with Trump supporters who are doing the victory dance in their faces.
I don't doubt for a moment that some of Trump supporters feel validated in their bigotry and are looking for opportunities to fuck with people they hate. Of course not every Trump voter is that way, but I doubt any of them will step in and stop it.