How Capitalism Is Generating A Global Third World Economy

In a nutshell, as capitalism matures, the ultra wealthy are simply buying more and more money out of the economy (investment income as opposed to productivity), so there's less and less left for the people doing the work producing the wealth, and less and less for those sacrificed at the bottom*.

(*Capitalism always benefits from higher unemployment, because it keeps the price of labor, lower as more people must compete for jobs--thus capitalism provides an incentive for higher unemployment rates. This constitutes "those sacrificed at the bottom.")

The fact money buys money (one doesn't necessarily have to produce wealth in order to gain in a capitalist economy) means the economic system is a feedback loop. It must be regulated since a feedback loop is unsustainable.

At this point the capitalist system is for the most part one global economy with some nation-state intervention, and the U.S. is simply part of it.