Hell, in a different context flooding countries with foreigners would (quite rightfully) be considered a form of genocide. It's well accepted in international law that trying to dilute a native population out of existence via immigration is genocide. Tibet (Han migration) and occupied Ukraine (Russians) both being recent examples.

There are certainly people in western countries whose hatred of white people is sufficiently nutty they their goal with unrestricted immigration is to genocide the white population out of existence (also, Jewish and Asian populations in some cases).