One definition of the middle class is to divide the wealth of America into five quintiles, of which the second through fourth quintiles represent the middle class; whereas the first quintile represents the upper class, and the bottom quintile represents the lower class. According to brookings.edu, "The top 20 percent held 77 percent of total household wealth in 2016, more than triple what the middle class held…" and further, "… the top one percent alone holds more wealth than the middle class…" This signifies that in America, the wealth disparity between those that have and those that are the backbone of America is astonishingly high, and that disparity is the prevailing reason why a significant percentage of middle class Americans are uneasy about not only their current position as it is, but are very concern about future generations as well as their fair opportunity to make something further of themselves.
That is to say, when a significant percentage of middle class Americans essentially live paycheck to paycheck, and therefore are susceptible to not being able to keep their bills current, are thereby especially in danger, if one of the members of their family loses their job for whatever reason, or if someone suffers an unexpected health crisis, or if they encounter some other unanticipated major expense; then this, quite obviously, cannot possibly be healthy for the American middle class as a whole.
In consideration, that America is the richest nation in aggregate in the world, one might think and basically one would expect, that the core of America, its middle class, would be secure not only in their employment, but also in their living, but this really isn't the situation whatsoever for many of those that are part of the middle class. When anyone, is employed at will, but are obligated to make payments, for example, on a mortgage for thirty years, and/or to make payments on their vehicle for five years or even longer, then what has occurred, is that the person that has taken on that long term debt, is trying to pay back and to stay current on that debt, often with a job that is not guaranteed to even be there, over that same period of time.
On the other hand, those that are very rich, have the best of the best of what America has, and more than enough to take care of not only their own self and family, but the ready assets to setup future generations to live just as well. That type of disparity between those that have, though they might indeed have worked hard, as compared to all those that are struggling mightily to maintain their position, is in its very nature going to create tension and unease within this nation, for the vast majority of Americans are not stupid, but are cognizant that it doesn't seem fair that so few have so much, and that so many, have so little.
There was a time, not so long ago, when unions were both stronger and relevant, when many employees were entitled to pensions from their company jobs, when those jobs were secure, and when taxation in all of its myriad forms, was truly progressive, but those days are now firmly in the past. Any nation in which the top 1% has more wealth than the 60% that represents the middle class is a nation in which the rich live at the expense of the middle class, and the middle class effectively serves the rich. That isn't healthy for that nation, it isn't right, and it need not and should not be that way, in what purports to be a free and democratic country.