Heather McGhee’s illuminating and hopeful new book, The Sum of Us, is predicated on the idea that while the primary victims of racism are people of color who are subjected to it, little will change until white people realize what racism has cost them too. Racism has costs for everyone. It is the common denominator of our most vexing public problems, the core dysfunction of our democracy, and a major component of the spiritual and moral crises that grip us all.