Originally, this term was coined by a professor at UMASS Amherst and used during a lecture to describe the shock students would receive when they went out into the real world and experienced the abundance of stupidity.
Although it mainly is used as a noun which describes a segment of the population, it has since evolved to also describe places or situations. It is usually reserved for stupidity, ignorance, etc. that is noteworthy or extreme. It is generally not used in hyperbole.
Superlative form: "Realest of Real America"
n. shopping at wal-mart? why would i want to go to the domain of real America?
n. I was pretty pissed off when "real America" in the Dodge Ram cut me off on the highway.
n. Steve: real America is a shitty place to live man!
Fred: Why the hell did you gamble at the Western? Didn't you value your life?
Jon: It was so real America, I had to see it for myself.