This is a crazy form of propaganda instilled by both sides of the political spectrum in the US. Germany's population is 82M+, and much more diverse than you think. You think you have nothing in common with someone in Alabama? At least you speak a common language and share a constitutional tradition. German unification was completed 60 years after Alabama was admitted to the union. A Schwäbisch person has as much in common culturally with an Ossie as you do with an Alabamian.

This 300M+ logic is the perfect strawman for people who don't want to solve problems, because the population of the US is only comparable to few countries in population and they are not in a good position...