From what I have seen Marx seems to have said a number sensible thins which still resonate. It is not clear to me what a Marxist is. It seems that a number of people have continued to work on his main themes. Anyway, Thomas Farrell says in his write up on "The Making of Global Capitalism: The Political Economy of American Empire" by Leo Panitch and Sam Gindin "The mainstream of American international political economy has cast off both its more radical connections and its ambitions to speak to larger debates. Marxists and radicals continue to work on international political economy, but they are largely ignored by the dominant figures in the field.
This is a pity — as Panitch and Gindin’s book shows, there’s a lot that they could learn. And if most standard issue international political economy scholars don’t know much about Marxists, the opposite is not necessarily true. Panitch and Gindin not only know the debates among radicals, but have read very widely across the field of IPE, engaging with (and often usefully repurposing) the ideas and empirical material that they find useful.
I learned a lot from their book, and will be assigning it to my students. Still, I think there’s room for useful argument. "