The Pew Research Center weighs in with a recent demographic report that contains much you already knew and some things perhaps you hadn't yet seen. One factor of which they make much is the decline of the middle class as a percentage of the U.S. population.
It is true, their figures show that during the period from 1971 to 2015 the middle class declined from 61% of Americans to 50%. If you believe our genius has derived from our massive middle class then that decline could be seen as a bad deal.
Now let's unpack the middle class declining by 11%, did all 11% end up poor? Not even close. Four of those 11 percentage points were people falling out of the middle class, ending up poorer.
On the other hand, the other seven of those 11 percentage points represented middle class people becoming more affluent! The "upper income group" grew by half, rising from 14% of the population to 21% of Americans.
In other words, of those leaving the middle class, almost twice as many (7%) improved their economic lot as opposed to becoming worse off (4%). I'd call that a cause for rejoicing, you should too. This is the "pony."
The rest of the report says as a nation we're becoming older, less religious, less white, and possibly more liberal. I expect many will find things in those sections to rue, reasons to believe the country is on the wrong track. This is the "manure pile."