Dehumanization is a standard and even necessary tactic for violence. It's difficult to commit violence against someone who is human just like you; it is in contrast much easier to commit, commend, or at least accept violence against non-humans. And especially against sub-humans.
There are a couple of images, however, that seem to really get these people going. The first is the idea that protesters are having sex in the open. I don't need to explain why that would excite them. But they seem to get even more stimulated by the notion that protesters are relieving themselves in public. When I was a kid living in the South, I remember my parents looking at a book that was being passed around featuring alleged pictures of civil rights protesters defecating in the streets.
The thing had the neighborhood all aquiver, it was like pornographic contraband. Just recently, Fox Nation got very overexcited by a story from San Antonio about homeless migrants without toilet facilities using an alley.They really love to show pictures of this sort of thing for some reason. ...
The left gets dinged, sometimes fairly, for wrongly imputing racist motives to the right wing. But it's clear that there is a strain of rightwing thinking that needs to see their rivals as as traitorous, animalistic beasts who screw and defecate in public. They cannot even be acknowledged as human beings who observe the most basic levels of decent behavior. I'm not sure that has anything to do with race, but it is a very primitive form of tribalism nonetheless. And it's exceedingly creepy to see famous talk show hosts evoke those images. If history is any judge, I would expect to see more of it.