And nominally peaceful protesters condone.

Peaceful demonstrations in downtown Chicago ended in a violent clash between police and protesters Saturday, leaving 17 officers injured and two dozen people arrested.
…
“Multiple agitators hijacked this peaceful protest,” Mr [Chicago Police Superintendent David] Brown said late Saturday. “This group deployed large black umbrellas, changed their appearance and began pushing and eventually assaulting officers.”

It’s not strictly true that agitators hijacked the protest.

If those “peaceful” protesters had truly wanted to stay peaceful, they would have dealt with the agitators in their midst before the latter could convert the protest to violence.

Certainly, that would be hard to do, but hard means possible.

At best, the “peaceful” protestors are shirking their personal responsibility and putting their obligations off on others.