Gotta disagree. I'll bet most of the protesters don't even know about that punch comment.
The MSM has been relentless, they've been painting Trump as a racist and a Nazi for some time now. And that lie has been repeated in student unions and leftist meetings. That's what has motivated most of those protesters.
I remember when Obama told his supporters not to bring a knife to a gun fight..I remember in 2008 when someone at a Joe Biden rally said they wanted to punch Sarah Palin the face, and Biden’s response “I just love you.” I remember a few months ago at a Hillary Clinton town hall a man said how he wanted to “Wring Carly Fiorina’s neck” and Clinton stood there and laughed..not a peep from the media, not one word calling those actions wrong