Rule of law: if someone brings a bat to a peaceful protest they need to be locked up. If they show up without weapons to counterprotest, then they need to be protected from violence (e.g. some idiot with a car). It's very simple, either rule of law, or rule of the jungle. Trump always wisely chooses the rule of law.
That's also the reason he doesn't perp walk Hillary. If there's a crime there it will get prosecuted properly and quietly sooner or later.
In regard to Hillary we been waiting 20 years and it seems later never comes...