Do you think Mao adhered to the system described in that paragraph?
Based on that essay, it's not clear how the dictatorship identifies 'the enemy' -- "the social forces and groups which resist the socialist revolution and are hostile to or sabotage socialist construction are all enemies of the people. "
As long as some of 'the people' are at risk of being designated 'the enemy' without clear criteia, there cannot be democracy.