How, precisely, does one conceptualize the operation of a system as complex as the United States? Or, more specifically, is the US best conceptualized as Luhmann suggests -- that is as a set of largely distinct systems (social, political, economic, legal, etc.) which each operate with all of the others as part of their environment -- or as Marx suggests -- that is as an integrated political economic system?
The fascinating figure below shows that for the past 60 years there has been a very strong link between the extent of income inequality (as the difference between the rich and the poor increases, so does the gini coefficient) and the extent of political polarization within the US House of Representatives.
Obviously, no single piece of evidence can unequivocally answer such a broad question. But, the figure below certainly suggests a very tight coupling between the Gini index (economy) and polarization within the House (politics); a scenario more straightforwardly consistent with Marx than with Luhmann
Those interested in the details of the research that produced the above graph will want to check out Polarized America.