The once all-powerful US economic engine is (at this point anyway) giving way to globalization and international competition. The once all-powerful US economic engine is heavily in debt and moribund with short-sighted politicians jockeying for power.
If the US wants to regain its previous economic might, it must invest very heavily in long-term research and development of new technologies. This is not happening worth a damn. Vastly more is spent on military intrigue; hell, vastly more is spent on pet food or cosmetics or any number of nonsensical expenditures. Alas the US is a victim of its own success.
Remember, there was a time when the sun never set on the British Empire; look at it now, the British Empire is a vague shadow of its former self. All countries, all civilizations in fact, have their rise and their fall.
Will the US become a backwater of ignorance, combined with a preoccupation with puerile superstitions such as Christianity, overseen by multinational corporations? Some (many?) would argue it's already happening!
Well time for another cup of Chamomile tea, as I don't have to worry being a rich Canadian with resources galore and a superior education system of which I am the natural product