I'm convinced America is headed very soon for another financial crisis similar to that of 2008. This time, however, the financial upheaval might spawn a collapse of the US government similar to the collapse of the Soviet Union. We are in currently in multiple bubbles and both private and public debt are beyond dangerous levels.
There is a measured rise and fall of every civilization following the development of agriculture. My cohorts believe that we became soft as a species when men no longer had to go out and kill mammoths for food. The United States will fail. People will continue to be people. There just aren't any more mammoths to kill. Just each other.