Recognize you are treading on a very slippery slope. Not so many years ago, the people in positions of authority would use your logic to prevent you from speaking or organizing.
Next, the Anfita crowd has repeatedly demonstrated their willingness to commit violence toward anyone they disagree with, including liberal college professors and unarmed women minding their own business.
Lastly, one 20 year old punk drove that car, and the people walking around with signs are no more responsible for murder than you are responsible for the violence committed by Anfita. Even the ACLU supported the free speech rights of the abhorrent White Nationalists in Charlottesville, and condemned the violence of both the protesters and the counter-protesters.
Protecting free speech rights has never been about protecting widely held opinions. The entire point of free speech rights is that it is the inherant right of individuals to speak their mind, and the government has no authority to stop them.
Let them speak. Bad ideas quickly wither when exposed to the light of day.
Worse, there are many who find the well organized attempts to silence others a far greater danger to free people and democracy than a few foolish racists.