Pure unregulated capitalism (which America is very much not) is Darwinian in how similar to natural selection. In natural selection the top of the food chain sometimes die off, but in general I agree with the GP poster.
To truly see who is more fit, I propose that we take a group of 12, 6 from each class, and drop them off on an uninhabited island. We will places weapons and traps at strategic locations. We shall call this experiment Project Craving Romp.