Twenty years ago, my history of how racism shaped Dallas, White Metropolis: Race, Ethnicity, and Religion in Dallas, 1841-2001, was published. I ended the book on a pessimistic note. “By the mid-to-late 1990s, Dallas represented a dispirited collage of mutually antagonistic fragments, a sum much less than its alienated parts,” I wrote. “If Dallas never exploded [in riots] like Watts, Birmingham or Detroit, it was not because it enjoyed a more dynamic leadership than those cities, but because of a self-induced paralysis that left the structures of oppression soundly intact.” Dallas today in some ways is not as relentlessly dysfunctional...