there's two sides to this. wherever you have class, you have socialism. but what is perhaps more significant is that the american elite has a long history of what could be called vulgar marxism.

"The influence of factious leaders may kindle a flame within their particular States, but will be unable to spread a general conflagration through the other States. A religious sect may degenerate into a political faction in a part of the Confederacy; but the variety of sects dispersed over the entire face of it must secure the national councils against any danger from that source. A rage for paper money, for an abolition of debts, for an equal division of property, or for any other improper or wicked project, will be less apt to pervade the whole body of the Union than a particular member of it; in the same proportion as such a malady is more likely to taint a particular county or district, than an entire State."

america has been willing to read socialist ideas and learn from them, but more often than not it has been to find ways to uphold the dominance of what is really still the landholding class.