Let hear from the man himself, Karl Marx
"But, in general, the protective system of our day is conservative, while the free trade system is destructive. It breaks up old nationalities and pushes the antagonism of the proletariat and the bourgeoisie to the extreme point. In a word, the free trade system hastens the social revolution. It is in this revolutionary sense alone, gentlemen, that I vote in favor of free trade."
How do you tell a Communist? Well, it's someone who reads Marx and Lenin. And how do you tell an anti-Communist? It's someone who understands Marx and Lenin.
--Ronald Reagan