For instance...free speech. For the common good, of course.
I grew up in San Jose, CA, and cruzed main street every Friday night for many of my teenage years. There is a heavy latino population there but not violent like this, and especially not for Politics, they fight turf, and internal politics.
This problem is not a local one, these are imported troublemakers, hired to incite violence, able to flee the state if they do damage. Police tend to clean up after a riot there, and not get involved during the altercation in my experience. Liberal agenda is rampant there, with no incentive to get themselves hurt over imported problems.
I agree, private security, that takes down troublemakers, that will work in concert with the police, with videographers that document their actions for probable complaints by the assailants would be wise to stop problems before they start. When professionals fight back immediately, agitator tend to leave quickly. Those stealing private property (signs, hats, etc), should be detained and arrested with video to prove they did it, and make them examples, going to jail and having their action put ON THE RECORD. Just my opinion.