Trump is essentially harnessing, consciously or unconsciously, the Westboro Baptist Church model of agitating people to the point of rash emotional responses (which can be, in these cases, violent responses). They spout their message, which put lightly, is divisive, and they push it until someone lashes out. At that point, the WBC stays pacifistic and plays the victim card, points to free speech (as does Trump, at least the woes of politically correct speech). Their message is more extreme than Trump's, so their appeal is less broad, but I think they operate similarly. It's basically the "not touching, can't get mad" move at its most extreme. Those who are responding violently are in the wrong and play into the hand of Trump's victim narrative, that is indisputable. However, much as Trump argued when his supporters acted violently (the old dude who punched the black guy who was being escorted out), looking at the violent actions without context might not be enough. People are not protesting Trump's rallies because his message is one of love and unity (though, I'm sure a Trump supporter could make the argument it is one of love and unity for "Americans," however you interpret that term), people are protesting because they are lashing out against something they see as fundamentally unacceptable. In this way, and you can argue about who is objectively correct in their rage, violent Trump supporters and violent protesters have the same fundamental motivation for their rage, just coming from different areas of the political perspective. This helps his narrative as a victim and a “counter puncher.” It’s like an inoculation against future violence on his supporters’ part, because he can push the narrative that they are just responding or countering violence they did not start. I’m not sure that this narrative will help him court democrats in anyway, but it may unify right wing support that is on the fence about him.