It is very worrisome that this man is a professor as he seems unable to see that a lot of the violence in US streets is caused by the left - Occupy Wall Street, ANTIFA, BLM all use masked protestors that are prone to violence.  Is it too much to expect today's professors to base arguments on facts and reason? How would he like to have some conservative tell him what he can say or write? The path he suggests leads to a very bad end (Mao, Pol Pot, Stalin, Hitler all had policies along the suggested lines).