https://www.americanprogress.org/issues/economy/news/2014/12/18/101790/as-income-inequality-rises-americas-middle-class-shrinks/
"America needs a vibrant and prosperous middle class to drive economic growth. Unfortunately, with the increasing economic inequality of the past several decades, the United States has become less of a middle-class nation, and those in the middle have found themselves increasingly financially squeezed and struggling to get by."