That does answer your question. Participation in white supremacist groups had gone down. The increase in participation is a cultural change. If you're referring to immigration, while all groups lean toward having a favorable view of immigrants, black people have a more favorable view than white people do.
So the cultural change white people fear is some rise in white supremacist groups. Okay. Then you mean legal immigration. Okay.
You apparently don't know how to follow your own conversation. If immigration were a huge issue for black people, Trump would have gotten more than 8% of the black vote.