So what if there's a "minority" majority? White people till act that like toward both black Americans and Spanish-speaking Americans. Black people can say unkind things to white people, but we are not the ones who live with the history of racial privilege, so we don't automatically treat white people as "lesser." Just because something happens a vast majority of the time doesn't mean it happens all the time. I am fortunate educationally, economically, and socially, so I tend to spend a great deal of time in predominantly white spaces and am subjected to this kind of crap far too often. Surely you, too, have heard of the horror stories of black celebrities who have been mistreated by the police or dissed in establishments such as stores and restaurants.
In fact, just because we're having this discussion, I'm reminded that as I was leaving my local Whole Foods, a representation of some political organization was soliciting signatures for a petition. He earnestly approached every white person in proximity, but he let me walk by without comment. Why? The only difference between me and the other sincere Whole Food patrons was my brown skin. Did he presume that I was uninterested in politics or would be unwilling to listen to his spiel? Again, why? Unfortunately for him, it turns out that I am very active politically and raise funds for Democratic candidates for national office. I would probably have been one of the most politically knowledgeable people he approached, but he never even tried. His loss. (Although, I knew the topic and would not have signed. He couldn't have intuited that simply by looking at me, though.)
I happen to be a DC native, and although blacks represent a substantial middle and upper-middle class, the wealthiest Washingtonians and the ones who have the most prestigious jobs in the federal government still tend to be white. DC, as I'm sure you know, is not as independent an entity as people may believe it to be. You are aware that it has no voting Congressional representation and its budget is allocated by Congress to this day. Either my family or I have subscribed to Washingtonian magazine for at least six decades (yep, it's true) and if you read through several issues, you would never know that blacks were a majority in the city. As I warned, due to indoctrination, we as a people often fail to give ourselves the respect we deserve.
I might add that although white people are the minority in Texas and Hawaii (as they should be, as they are not ethnically indigenous to those places) I'm pretty sure that they control the political, social and economic governance there. Yes, there are politicians of color in Hawaii, but they tend to be Japanese rather than native Hawaiian. American racism is systemic and persistent, and though most white people may believe themselves not to be racist, they carry implicit privilege with them. As for children, my last paragraph was a warning to pay attention to how we speak to children, because we treat them as "lesser" as well. I hope that this answers your question. And, no, it doesn't make sense because racism should never make sense.