>Except they did call the cops, who showed up and then did nothing.<
That's easy to fix!
Protest Target: "Hello?"
911 operator: "911, what's the nature of your emergency?"
PT: "Yeah... I called about a mob outside my home. I'm at 123 S 4th st"
911: "Yes sir... officers have been dispatched, but they're afraid of doing anything to antagonize the crowd"
PT: "that's fine then. I'm barricaded in the living room with my AR, in case they decide to force entry"
Something tells me that conversation would have police responding, quickly.
Another phone call which might help a bit is to all the local broadcast media outlets.