This article in the Atlantic highlights something that I have been thinking about a lot over the last few years, namely the issue of what defines the middle class. In it, Ta-Nehisi Coates points out how the campaigns stress traits like "'playing by the rules,' 'hard-working.' and 'middle class," and rightly wonders why only the middle class gets the label of "hard working."
For me, this highlights one of the things that I find the most strange about modern american culture, namely that it seems like almost everyone claims the status of middle class whether or not they have a great deal of money, or no money at all.
The term is so wide that we have both an actual class system that was created in this country over the last couple centuries, and income brackets that both lay claim to the title of middle class. So its possible to be middle class, that is act like a person from the "typical" american family, while being dirt poor. In this sense being middle class involves things like valuing the concept of going to college, generally being a "good citizen," expecting to be able to find a steady job that allows for ideas like the American dream, that sort of thing. Where you are on the income bracket does not matter so much as how you act. The rags to riches success story does not leave the middle class by becoming a multi-millionaire, at least if you understand it as a set of ideals.
One thing I have to really give praise to in the originally linked article on this point is that Ta-Nehisi suggested looking at Appalachia for an example of non-middle class people, as it really is one of the only places I have ever been where I met people who were proud to *not* be part of the middle class. The other places I would look for those few people who aren't "middle" in this country would be lower income minority neighborhoods and people who come from multiple generations of wealth, neither of which are groups I have had enough contact with to write about with any authority.
All this is opposed to our income brackets, which also use terms like "upper middle" and such. This creates the weird situation where the expensive RV owning self identifying redneck who happens to make a 100,000 or so a year would be both "upper middle class" and a "redneck" at the same time, categories which should to my mind be mutually exclusive. But somehow, probably in the 50s by my guess, we managed to effectively eliminate all of the classes except the middle class, to the point that distinctions like working class vs gentry are mostly meaningless even while the monetary inequality remains.
All this said, there are worse class systems out there. To pick one of my favorites, the ancient Athenian label for being a respectable sort was kalos k'agathos, "the good and the beautiful." To massively oversimplify, if you were pretty in ancient Athens, then it could be assumed that you were from a decent family.
It seems absurd, really, but even today you can see how such a system of categorization would come into existence. All of the factors that John Scalzi writes about in this old post on the subject of being poor all lead to a reality where you can tell at a glance who is poor and who is not by how they look physically, this was even more true in a world where the *only* health care was for the wealthy. We have created a myth of a universal middle class, but I often wonder how long an idealized middle class can last and whether we will see a return to a more stratified set of ideals as the income gap grows.