@engineer,
Let's be clear about what we are talking about.
The Black Lives Matter protesters are looting, setting businesses on fire, and attacking police officers (just like the Trump supporters did).
It is your right to protest an election or a trial verdict that you think is unfair. I think either is stupid (these are democratic institutions that shouldn't change with protests), but protesting anything is your legal right.
It is the justification of violence that is the problem.
I am not comfortable making the link of these acts of violence with "civil rights marchers".