Looking at the pictures nearly all the black demonstrators appear to be female. That's another calculated measure to prevent blow-back. After all, men don't hit women -- unless they happen to be black like Ray Rice.
Well, you don't have to deck your opponent in order to defend yourself. If the she-animal is making unwelcome contact, she is committing a crime and a tort. Just fend off the blows.
The protesters are inviting and deserve disrespect, not that they won't claim they are entitled to respect.