About 19% of the US is immigrant compared to like 17% in Germany, so they are fairly similar. Can they bring the rest of Europe along though? It’s a huge challenge…
According to the UN, in 2019 Germany had 15.7% foreign born and USA 15.4%.
And the AfD notwithstanding, Germany has the pragmatic Gastarbeiter precedent.
The larger precedent, for all cultures, is that idealistic views (immigrants good! Immigrants bad!) fade dramatically and rapidly when pragmatic issues emerge.