And this is no small country...

315+ million population used to the easy life, at least easy relative to the rest of humanity, with the convenience of a seemingly and mistakenly untouchable religious culture.

The OP's premise is all well and good under logical, reasonable conditions. The democracy of the US has been successful, could have been more so, and may still be, under logical and reasonable conditions. What is happening to undercut our democracy is not the weakness of the constitution or the weakness of the administrative powers or the incapable disjointed congress, it's the weakness of it's people both in government and the general population to have been duped by a scheme to destroy it. How do you destroy a government? a democracy? You look for the human weaknesses and accentuate them slowly over time.

Our weaknesses? Our weaknesses are our strongest points turned inside-out:

Our advantage as human beings has been our ability to think... degrade that till we are a nation of dumb. Another advantage has been our ability to adapt.... accentuate greed and we become a nation incapable of reasonable compromise, empathy and civility. An advantage? Our ability to imagine and create.... twist that into impassable, unchangeable dogma that demands the world to see their imaginary vision as fact, indeed the demand to accept their belief or die, and you foster the inability to learn, to be incapable of learning. This is what has happened to us as a nation. We have become dumb and numb. We have become unable to see each others needs, joys, hopes, pain. We have become a nation burdened and drugged by the irrational.

We are not following the good natures of humanity, we have succumbed to our ancient nature which has made our government, our democracy, and ourselves as humans vulnerable. We are becoming incapable of expanding on our greatest advantages.