Free speech and the right to peacefully assemble and protest are part of the Constitution. Making moral judgments about the speech or the views of those assembled is not the place of government.  Protection of unpopular speech and views is the reason the 1st amendment is good. When government in the former of law enforcement protects some speech and allows holders of other views to be beaten to a pulp, the Constitution and civil rights are violated. 

We used to have a saying that "I completely disagree with what you say, but I will defend your right to say it." Our Republic is in danger when some views are allowed and others are punished by withholding legal protection.