Thanks for an insightful comparison between the U.S. and Germany.
These same groups in the U.S. also seem to conveniently forget who the "real" Americans are and how they were exploited and eradicated. Denying the injustice that to this day still looms large against both Native Americans and African Americans (as well as various other minority groups) is very telling of the U.S.'s unwillingness to admit its mistakes. We can't just cancel what's inconvenient and ask everyone else to pretend like it didn't happen (or that it was in the past and people should get over it) and move on.