[magduf]

>Japan, Korea, Germany are also in line and also India (with successful space program without immigrants).

This is just plain wrong, in the case of Germany. Germany has a huge immigrant population, and has since WWII when they brought in tons of Turks to be laborers there. There's an enormous Turkish population in Germany, and it's not new. Germany probably would not be where it is now without them.

Japan and Korea don't have many immigrants, it's true, but they were both occupied by the US for some time (and Japan still is, in a way, as is Germany).

[rayiner]

80% of Germany is ethnic Germans (including repatriated Germans). No U.S. state is that homogeneous.

[magduf]

20% immigrants is still pretty huge for a European nation.