Free trade destroys our infrastructure and social structure of work and wealth creation and hastens the revolution. Marx was definitely a free trader.
Yes, and conservatives are stupid to support free trade uncritically.
Note: I am not in favor of “fair trade” or other subsidies to unions or US corporations.
“...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. “ - Karl Marx, 1884