Hose them down... use the water canons to cover them all in Super Glue.
I have said and believe that Trump should say, “The nation id broke. Obama spent us so far into debt we can’t afford a traditional inauguration.” Then he should rent a hotel ballroom in some city other than DC and have the chief Justice swear him in there. record the event and then put it on You Tube completely bypassing the networks.
This would allow the Sh*tbag protesters to protest but would remove the focus. It would also make the point that Trump is serious about reducing the budget deficits
A flame thrower, if they got to close, would be a nice touch,too. Plus it would warm them up after getting wet.