I doh't think that structure was true. The studies all say the same thing - that one is able to achieve success if one has rich parents, and no matter how talented one was or how hard one worked, if one was born to poor parents, one remained poor.
The American structure was that of an oligarchy, and it seems that it always has been, except for the years one had a mixed economy (a bit socialism, and well regulated capitalism).
The problem here is not a fight between the conservatives and the liberals. The problem here is that both are advocating a neoliberal economic system, i.e. a brutal economic regime where if you're at the top, you retain all the wealth.
Both the liberal elite and Republicans support the neoliberal economic regime.