He can't do it unless he has evidence to present that they are violating the Constitutional Rights of citizens with the backing of local and/or state government.
Besides that,he SHOULDN'T try to save them from themselves. They wanted it,they created it,so let them stew in it.
There is nothing you can do to discourage such conduct in the future that would be more effective than letting it run it's course today so everyone can see the results of where anarchy truly leads.