International polarity and America's polarization

There is a growing consensus that the United States is undergoing a period of political polarization, particularly among elites. The causes of this polarization remain under-researched. We argue that shifts in the international distribution of power influence America's polarization. To demonstrate the argument, this article analyzes changes in power and polarization quantitatively and qualitatively from 1945 to 2005. A key finding is that greater relative power on the world stage substantially increases polarization and some of its correlates, like income inequality. The argument also measures the extent of international influence on domestic polarization and makes novel predictions on when and why polarization will fall.