She's been there all along, the African-American woman, the most loyal and stalwart voter any Democratic politician ever met. You just didn't see her . So steadfast is she, exercising loyalty to her party, to her race, to her gender, to her country, that her support over the course of decades has long been taken for granted by Democratic politicians able to appeal to that set of loyalties. Embodying the intersection of race and gender, the black woman voter was, in years past, rendered invisible, as the bloc known as "the black vote" took on, in the popular imagination, the face of the African-American man, and the one known as "the women's vote" was given a white face. What irony, then, that this time, in this primary season, when the two main candidates in contention for the Democratic party presidential nomination each wear the assigned face of one of those blocs, that the black woman is, for a moment, revealed as an entity in her own right -- and...