Sargon has an important video on the Alt-Right and Antifa (the “Alt-Left”). The video is just under twenty-nine minutes.
I agree with Sargon that Antifa and the Alt-Right are both problematic because of their collectivist, identity-driven ideologies. They are both enemies of liberalism (classical or social), as all forms of collectivism and identity politics are.
It is unfortunate that the media refuse to expose the violence of Antifa. These people are communists, anarcho-communists, and anarcho-syndicalists. These ideologies are dangerous. Not only are they willing to use violence against anyone who disagrees with them, but their types of ideology has led to the deaths of millions of people around the world.