Churchill once said "America always does the right thing, after exhausting all the alternatives." So it may just be a case of waiting for the moment of exhaustion. Not a happy thought.
I do think America's Constituted institutions, though flawed, contain countervailing resources out of which repairs and progressive reform would indeed eventually assert themselves to the good.
But the long run of theory, as Keynes crucially reminded us, is one we may not live to see -- and no theory worth anything is indifferent to the terms in which the actually living actually live.
Climate change and resource descent have a time-table our institutional checks and balances are very probably not equal to. I don't think the planet can afford America going crazy and throwing a tantrum right now, but that's what is happening. Arms proliferation and mass-mediation (of which panoptic surveillance is a part) exacerbate the ways in which the instabilities and violences born of climate change and resource descent play out beyond healing.
Had America seen sense and shifted the ship of state decisively in the direction of secular sustainable social democracy with Obama, and decisively marginalized our white-racist theocratic bullying impulses (that clammy ill-smelling Tea Bag was always there, from the very beginning of our story) we might have deployed our shored up authority and immense resources in the service of social justice and sustainability on a planetary scale.
But that's a receding Mouseketeer dream, probably not in the cards anymore.
What is needed is good sense, and though there wasn't enough of it in the class of 2006-2008 it did seem the US might have turned the tide toward sense. But we have failed. It's not true that you really get infinitely many chances to screw up. People really do die. Civilizations really do fall. My inner Mouseketeer suspects we may have arrived at such a point, I suppose.
At such a point, the only viable check on America is for the rest of the world to marginalize us into comparative irrelevance and get to work on real planetary problems without us as we feast idiotically on one another in the aftermath.
As an American, I can't say that prospect is particularly cheering, so it's something of a hopeless hope... A hope for a planet that survives the technoscientific forces we unleashed, and for an educated critical convivial consensual commonwealth that tames those forces in the service of equity-in-diversity. The US simply may not be capable of partnership in that planetary project after all. What a terrible desolating waste it is.
The post-WW2 eyeblink Empire of the US that fancied itself the planet's hard-cock, policeman of the world, can be reduced instead to the Germania of an EU/UK Commonwealth/South American Global Rome, we can be the unruly embarrassing backwater whose miserable unwashed uneducated masses grimly provide the dispensable cannon fodder for civilization's ongoing skirmishes. China can play Parthia, the eternal specter of antagonism, but too preoccupied with its own internal social struggles and ecological crises ever really to do much more than bark. Maybe a sustainable equitable diverse planetary polity can emerge out of that dynamic in the long run.
If it does, you can be sure that it's a long run in which we will all be dead... after lives spent in hopeless heartbreaking struggles for sustainability and sense and social justice waged in the face of a suicidal uncomprehending unbending gale-force idiot wind.