I'm not saying this is why Trump won, I think it has more to do with a global pandemic that hurt a LOT of people and instead of processing that pain, we blame others, and Trump is good at blaming others. But also, if you feel lots of pain and Democrats say life is great, you don't believe them because your life doesn't feel great and someone who says "Make America (you) (feel) Great Again," well, probably gets your resonance and vote.
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