Diversity makes people isolated and withdrawn, conditions that go alongside paranoia. Xenophobia, or the pragmatic recognition that other groups want to dominate your group, can also coincide with paranoia. But in the end, ethnic allegiance is more important than cross-racial alliances. We can see this in the case of Donald Trump and John Lewis:

Shortly after arriving in Atlanta, Trump signed a bill that grants Georgia its first national historic park at the Martin Luther King Jr. National Historic Site near downtown Atlanta. He signed it shortly after Martin Luther King Jr.’s niece, Alveda King, boarded Air Force One. The measure was long championed by U.S. Rep. John Lewis, an Atlanta Democrat and vocal Trump critic, who praised the bill without mentioning the president.

In theory, Trump is reaching out to another ethnic group, but this is not praiseworthy in the eyes of a member of that group. If he acknowledges the help of a cross-racial ally, he is ceding some power to that other group, so he cannot both recognize the help and maintain his own action in the self-interest of his group. This is yet another reason why diversity will never work, but in the meantime, will make unintentional enemies of us all.