"preserving the culture" is and always has been a dogwhistle for fascists. it's what the germans, italians, japanese, all of them were doing. if you believe "the muslims are invading europe so they can outbreed the white people and take over europe" is a legitimate viewpoint then you're handicapped.
here's a little shocker: there isn't a culture here that needs preserving. if there are more black or hispanic people in the US than white people then the only difference it makes is that there are more black or hispanic people in the US than white people.