The United States has always been too big and diverse to govern effectively. Even when we were thirteen colonies along the eastern seaboard there was division between the north and the south. As the country got bigger the divisions got deeper. A tragic civil war seemed to solve the problem but it didn't really do so. It's amazing that we have lasted as long as we have without balkanizing, not only because of regional cultural differences but also because we labor under a governing framework which is not nearly as exquisite as secondary school propaganda would lead us to believe. The founding fathers did their best at the time they created our basic government, but problems such as the electoral college, lifetime appointments for Supreme Court justices, and opening the office of president to any hooligan who can meet the basic requirements (lookin' at you, Trumpie-poo) are all coming home to roost in an era with communication capabilities the likes of which Madison, Hamilton, et al. could have scarcely imagined. The internet and 24-hour news (both often with a good deal of propaganda thrown in) are exposing clearly our fault lines. We have external enemies, but if the U.S. falls it will be primarily from within.