While there are many attributes, achievements, and accomplishments that have directly or indirectly contributed to making America the greatest and most powerful nation that the world has ever known; one of those very important contributing factors was the creation of America's middle class. That is to say, before the middle class came into fruition, most of history in any civilization was a history that clearly divided the relatively small ruling class from those that were ruled, of which the military and justice units of that civilization clearly were under the thumb of that ruling class.
This meant that the power structure of nations were built around the ruling class, consisting of nobility, the largest land holders, the largest business owners, the favored religion, and the elite of the military/policing arm of the nation. All others, for the most part, no matter what the law did or did not say, effectively did not own the land that they trod upon, and therefore the production that they created as farmers, small business owners, or artisans, was subject to onerous taxation from the ruling class, or outright theft of it, or was subject to confiscation for any reason and at any time. Further, those that owned absolutely nothing, had little option but to become part of the military force, necessary to protect and to augment the nation, of which, at best, doing so, providing a living, honor, and some opportunity; and at worst, resulted in their tragic young death.
America, on the other hand, in its formation, to a significant extent, made it point, to forget and to discard the titles of all nobility, as well as to dismiss the fortune of those that inherited wealth, without laboring a whit for it, to construct a nation that was built upon meritocracy, and to the degree that America did this, is the degree that America rose as a nation, providing to many that came here with nothing, but the willingness to work for their living, a fair opportunity to make something of themselves, of which this mighty nation therefore did so.
As Peter Schiff has stated, "The American middle class used to be envy of the world," and perhaps it would be so today, if the middle class of America was still vibrant and growing, but alas, it is shrinking at an exceedingly rapid rate, for as reported by npr.org, Pew Research Center indicates that in 1971, 60.8% of all Americans were middle income, whereas in 2015, that number had dropped to 49.9%. So that, what has occurred is that there are now more high income households, as well as more low income households, and significantly less middle income households.
Further to the point, household ownership today is no higher than it was in 1971; however, in 1971, national consumer credit card debt was virtually non-existent, whereas today national consumer credit debt is approaching $1 trillion. So too, student loan debt in 1971 was negligible, yet today that debt is approaching $1.5 trillion, and still growing higher at a phenomenal rate. In regards to car loans, as reported by 247wallst.com, in 2017, "The average length of car loans has reached 69.3 months", whereas in 1971, there were no car loans exceeding even 60 months.
When a significant amount of the population is in debt up to their eyeballs, when labor unions have been eviscerated, when those that have no real viable future are forced into military service, in order to secure employment, security, and health benefits, and with the world's highest incarceration rate; than clearly America of today, is reaching back to the empires of the past, that had a ruling class of which the lion's share of everything was theirs, and all others effectively served that class.