"...real threats..."
They are out there. They will be coming. Mass murder is a wholly justifiable tactic to them.
It is only a matter of time before one of those crazed psychotics joins a "protest group" and lets his inner freak start flying at their next event. Worse, yet, there could be more than one in attendance. The bar to violence gets lowered with every repetition of a harassment action.
The local authorities in DC will do nothing. They are tacit allies of the Leftists.
Avoidance and evasion are the only legal remedies left. That will not be sufficient in many cases.