I think there's a number of issues with this diagnosis, but chiefly: Trump won a second term on the back of a massive surge in non-white support. He's basically where he was in 2016 with white voters.
But about why people are upset about DEI, I think that has more to do with white people, especially men, not feeling well. Unless there's a huge portion of non-white people who have such vitriol towards DEI. I think maybe some of the Asian-American population, but I don't know about other segments. But im open to being wrong on that