There are two of these ideas, espoused by the alt-right, that we will focus on here:
Are you saying that nobody else believes this?
(1) racial and ethnic demographics are powerful indicators about our values and other things we care about, and
I don’t believe this is correct. Racial and ethnic demographics are not indicators of anything until you bring culture into it. A black executive and a black gang-banger are powerful indicators, but not because they are black, but because of the culture they embraced.
(2) culture, and more specifically our culture, is (in some cases at least) superior to other cultures.¹
Sure it is. It is superior because it is what we have chosen (either by moving here, or by not leaving). If someone moves here, they are expected to embrace our culture. This is what it means to be an immigrant. If you want to retain your culture, stay in the country you came from (or pick another country which shares your cultural preferences).
If you move to France, you are expected to become French. If you move to England, you are expected to become English. If you move to Italy, you are expected to become Italian. If you move to the United States, you are expected to become American.
I spoke about this here: