@Theaetetus,
Fido, please don't let the enormity of America's debt mask the genuine enormity of its wealth. America remains an immensely wealthy country but far too much of that wealth has been distributed by institutions that would transform democracy into oligarchy.
You might be interested to read
American Theocracy by former Republican aide Kevin Phillips. He traced the rise and fall of the earlier global monoliths - Holland, Spain and England - and identified a pattern of a process which your United States is following today. Each mega-state began with humble, agrarian roots; rose to the the dominant economic engine of its day and then decentralized its economic core (outsourcing) in the belief that its bright, shining future lay in financialization. It raises eerie parallels to the
FIRE economy (finance, insurance, real estate) that has evolved in the United States, displacing once mighty manufacturing, and leaving in its place short-term wealth spawning a succession of burst bubbles. He discusses at some length how a
FIRE economy creates an illusion of robustness yet is far less resiliant in the face of severe economic downturns than a manufacturing-based economy.
The steady demise of America's middle class, the decline of social mobility and the stagnation of wealth for the working classes, blue and white collar, are all features of the financialization of a nation's economy.
Democracy has the power to right this keel but that ultimately depends on an educated, informed and engaged electorate with the motivation to exercise its franchise to demand a better deal. America does face an enormous debt crisis, one that can be readily exploited to manipulate the public, but it is not insurmountable if the collective will do do that can be rekindled. If, however, the American people can be persuaded, through deception and fear, to continue to embrace 'everyman for himself' politics, I fear it's over.