Webster's dictionary defines conundrum as "an intricate and difficult problem." That fairly well describes our national preoccupation with persistent problems of race, its companion, racism, as well as our understanding of two related terms, ethnicity and diversity. If our understanding of these terms is inadequate, then it is impossible to meaningfully discuss them.
First, according to science, the concept of race is a complete fiction. For the most part, when we speak of "race" what we are really talking about are characteristics like skin and eye color, hair texture, and facial features common to distinct groups of people: white, black, brown, yellow, and red (Native Americans). These outer characteristics account for less than 0.1 percent of the differences among the groups.
In short, big-brained human beings constitute only one race, or species: homo sapiens sapiens (the wise ones). The difficulty here is that people conflate "race" with ethnicity. The are different. Ethnicity is about your DNA and ancestral culture. In this, it suggests that no group is superior to any other. We cry the same. We rejoice the same. We bleed the same.
I suggest the notion of "race" and racism are fairly modern (15th inventions 15th century to the present). The perversely understandable, yet fiendish purpose was about economics. It justified the superiority of one group over another, the consequent annihilation of native people of color around the world, the enslavement of millions of African Americans, and vast territorial acquisition and conquest.
As to ethnicity, a respected liberal journal of sociology, Sociology Lens, reports: "In the U.S., whites are the dominant ethno-racial group, however, this group has been ignored in the race and ethnicity literature." From what I can tell, that is true. As ethnic groups, and in varying relatively small percentages, America's whites are of Russian, German, British, Polish, Scottish, French, or a dozen or more other ethnicities.