John Edwards is often derided about his "Two Americas" conceptualization--it sounds dualistic and unrealistic, as there's really a whole range comprising the distribution of wealth in America. But it's really not too difficult to define exactly what the distinction could otherwise be.
It's basically a capitalist arrangement: there's the working class that produces the wealth, and there's the ownership class who reaps the rewards. (Edwards has defined it in similar terms--but is there a clearer distinction?)
Obviously, one America is the working class, who really have no choice but to work to earn a living (most want to limit risk-taking because they want to care for their family or be responsible for themselves in some other way, so "free enterprise doesn't directly serve the interests of responsible people in the economy).
Since capitalism requires unemployment to keep the price of wealth down (forcing labor competition--thus driving down wages, thus driving up profits for parasitic shareholders, comprising a race-to-the-bottom feedback loop), I usually include the unemployed among the working class element of production, since usually the unemployed are thereby forced to make some of the greatest sacrifice.
The other America then, by this definition, is the investor class: merely owning stock contributes zero to the production of (or decrease in) wealth for any particular business. For example, I can purchase shares (such a transaction is an equal value-for-value trade, apart from speculation) of a company without ever even knowing the name of the particular business or anything about it at all; yet I can still take profit from it via merely owning share while contributing zero to any production of wealth. Yet stocks are invariably the primary means of wealth for the wealthiest. This is the other America.
There used to be a whole range in between these "two Americas"--the great middle class--but guys like FDR are long gone.
The good news over the long run is this arrangement is, for obvious reasons, unsustainable. So maybe we're due for some modern versions of FDR.