Since this thread is inspired by the kerfuffle of Trump’s infamous campaign soundbite, I suggest that the only valid question is, what the hell did Trump mean by “America Great?”
He has never answered that directly, no doubt because of what and who he has always been: a promoter. Not a true leader.
Whether you talk politically or commercially, the idea of a country being “great” is just an emotional fantasy. Not a measurable fact.
So perhaps the question should be "what was the world like the last time most Americans THOUGHT the country was “great?” And of course, if you are honest, you will answer as well, the sub-question of “were we ACTUALLY great, or just (as usual) living a puffed up self-delusion?”
We can only guess, since Trump doesn’t say ANYTHING truly honest (he doesn’t always lie, but he never allows anyone to hold him responsible for anything he does say).
I would guess that what Trump is PLAYING ON, is the fantasy version of what America was supposedly like, in the 1950’s and early 60’s.
During that time, most Americans THOUGHT we were the greatest nation ever, because we’d been on the winning side of WW2, and because our propagandists had no competition, we didn’t realize that actually the USSR did the most to defeat Hitler; and because all the other industrial nations had been bombed into dust, and we had the only intact world-class factories, our economy took off like a ballistic missile; labor unions were successfully forcing wealth to be shared with laborers more reasonably; the idea of benefits and happy retirement was just getting started;
… and more than anything else, Americans luxuriated in the wonderful new era of TV entertainment, all of which was censored like crazy, so as to eliminate any HINT that the US was anything but fabulously and magically, God’s gift to planet Earth.
The reality was, we know now, decidedly different.
But I think all in all, that the key to the whole "American Greatness" thing, is understanding the desire to relive the ILLUSION. And since trying to bring an illusion to life is invariably "problematic," I anticipate Trump's efforts to result in, shall we say, "untoward difficulties."