FWIW, I agree with Pete. The news story is all over the place.
It defines "middle class" too loosely. At times, middle class seems to be about education. At others, occupation and earnings. In other instances, it is about home ownership. Then there's the question of upward (and downward) social mobility. Penultimately, there are the issues of geography (from South to West and rural to urban) and culture (what does it mean to be 'middle class'?). And finally there are the issues of age and generation. (Would it kill anyone to pay at least some lip service to gender?)
All in all, it reminds me of a story African American middle class that was published in the
New York Times Magazine this past summer. That story, available
here, had a similar (lack of) focus.
If I sound bitter it is because I am. News stories like these highlight differences between the African American experience and the "mainstream" of American society at the expense of showing the similarities.
IMO, these differences are critically important, especially to historians and other academics to say nothing of the people who experience those differences first hand.
Yet focusing on them in such an inchoate fashion may prevent Americans from understanding that they can draw positive lessons from the experiences of their fellow citizens regardless of class, race, region, ideology, and gender.