Dress to blend in so they think you're one of them and take lots of pictures and video.
If they believe you're one of them they'll freely speak their minds.
Get it on video.
If they threaten violence or get violent you'll have their faces to identify later. Post the video on youtube.
Show the world what they really are.
GREAT IDEA!!! No sarcasm.
Remember in berkley last week the jury found those that beat up a Trump supporter (who also had witnesses) NOT GUILTY ...................you can have all the proof on film and it does not matter. Ignore the left - like a kid when no one is listening, they stop