It explains a lot about MAGA world in general.
I hate to say it, but I saw this firsthand with my Dad. For whatever reason, he was unable to get into the Houston Fire Dept in the early 70's. In his 22 year old brain, "his" spot was given to someone "not as qualified" because of "affirmative action." I heard that refrain a LOT while growing up in his house.
My Dad matured over the years and went on to great success in another career, but that one rejection in early adulthood bent his brain on this issue. When MAGA went full-on grievance politics, that DEI issue resonated with the bent piece of his brain and sucked him in.
So my Dad, Charlie Kirk, and millions of other (mostly) white people who didn't get exactly what they wanted from life in their formative years found an easy scapegoat for that disappointment and aligned with a movement that gave permission to their anger and distrust.
At least that's my theory.