I don't blame been drinking for his ignorance. It is only a result of 50 plus years of anti-communist propaganda. It’s arguable that Communism has been the single most influential intellectual development of the past 200 years, yet very few Americans actually know anything about Communist ideology.
I'm sure been drinking doesn't understand that Marxism is basically a system of analysis, a way to view the world. Communism on the other hand is basically a form of government, or condition of society.