Every American should be outraged at white supremacist neo-Nazi hate groups that desire to take this country back to the dark ages and take away basic human rights afforded by the US Constitution.  The Civil War was anything but - however it was decided long ago.
While violence is not the answer, awarding Hitler Nazi's a platform of free speech is true idiocy.
That is where it starts.
If you literally threaten to take away American citizens rights, you can expect them to fight vehemently to stomp out the scourge that spew such things. 
If fascists are not glorified in public marches, there will be no answer by "antifa" or whatever you want to label it. If you slap someone in the face, do you really expect not to be slapped back?