In common discourse in America, at least, "middle-class" doesn't really seem to mean either of these things. It generally seems to refer to people who are not r

In common discourse in America, at least, "middle-class" doesn't really seem to mean either of these things. It generally seems to refer to people who are not recognizably in poverty, but are not recognizably wealthy either — think of the stereotypical '50s atomic family that you've seen on so many TV shows, which owns a home and a car and can reliably put food on the table, but is still strongly dependent on wages and can't afford a large amount of luxuries. So when people talk about the decline of the middle class, I think they mean a decline in people who are not obviously poor or rich, and instead fall "in the middle."