Note: defining what "middle class" is tough, in the context of survey respondents and their interpretation of what that is.

http://www.pewresearch.org/fact-tank/2016/02/04/what-americans-say-it-takes-to-be-middle-class/

What does it take to be considered part of the middle class these days? The vast majority of American adults agree that a secure job and the ability to save money for the future are essential. The public is more evenly split when it comes to owning a home and having the time and money to travel for vacation. But one thing is now less likely to be seen as a requirement: a college education.