You know how fights happen in hockey? Usually when the referee allows cheap shots and doesn't punish dirty players. Then one of the team sends their goon on the ice to punish the guilty. The ref has lost control of the game and somebody is going to get hurt. It is the ref's fault. If the authorities keep allowing violence by Antifa and do nothing, soon the other team is going to send in their goons. And somebody is going to get hurt. And it will be the authorities' fault.