America's middle class may be in trouble -- but what it means to be in the middle class depends on who you're talking to. A recent Gallup poll found a growing segment of Americans referring to themselves as "lower or working class" instead of "middle class," while a New York Times article suggested that the term was dropping out of favor among presidential candidates -- Hillary Clinton, for example, uses "everyday Americans," while Scott Walker is partial to "hard-working taxpayers." “It used to be ‘middle class’ represented everyone, actually or in their aspirations, but now it doesn’t feel as attainable,” David Madland, the managing director of economic policy at the Center for American Progress, told the Times.