Start with taking said diplomat

and throwing his ass out of the country.  Then take notice that a bunch of people planning
...“mass marches” on Inauguration Day in Washington and another one in Chicago on Saturday; the group hopes to “shut the streets down” at both rallies.
probably isn't planning for non-violent protests, and be prepared to deal with them.  They actually STAY non-violent protesters, fine; they start blocking roads, breaking things and otherwise rioting, to jail with them.