150 years most Americans would have viewed the idea of the "American Nation" as a unifying characteristic between the residents of the several states as laughable. "The United States" was a plural noun into the 1890's, an uncomfortable power sharing agreement between a set of very different people and states. If one completely arbitrary nation can be formed around common ideals and agreements to not kill each other I see no reason it couldn't happen on a much larger scale.
Trump's mindset is frozen in an outdated nationalism that, god willing, will not exist within a generation or two.
150 years ago they had just fought a war to defend the unity of the American Nation.
