You hit on the actual, practical issue here -- resentment -- and I think the Left underestimates its profound importance.
I see two elements at play from the Right's perspective. First, there is the old fashioned, mouth breathing, buttcrack scratching, ignorant, bigoted, manipulated, paranoid racism that you and I goddamn well both know still exists. We certainly see plenty of it on this board, and we're both called evil Hitler commies for pointing it out. And to me, even worse is the way it's denied and enabled by so many on the Right.
But there is another element here that I think is far more reasonable. There is a resentment that builds over time when one group is singled out for different treatment, i.e., we're going to provide an advantage to this person over that because of the color of their skin. A modern American is not responsible for our sins of the past, yet they have to pay the price for them. As a result, the resentment builds and builds and builds. And guess what? Trump wins. Trump wins.
Whenever I get into this conversation, I'm reminded of a great skit Eddie Murphy did on SNL, below. In the skit, he disguises himself as a white person and discovers how wonderful and glorious and easy life is when you're white, and how people just give you goodies and money for no reason.
This is why I don't understand what the actual goal is of many political tactics. My goal regarding race -- and coming from and married into mixed race families, this is important to me -- is that it no longer matters in everyday life. That racial tensions become a thing of the past, and not something that we keep exacerbating. It seems to me that the ends of this argument don't share that goal.