Of course, the explanation for her loss must be sexism. Elizabeth Warren cannot believe that she was defeated by the campaigns of Joe Biden or Bernie Sanders — she insists, instead, that she was defeated by their testes. We sympathize, truly. It is difficult to believe, and must be tough to accept, that any barely competent political operation could be defeated by the steadiness and freshness of Joe Biden or by the suavity and wide-ranging appeal of Bernie Sanders. And Senator Warren likes to think of herself as more than barely competent but omnicompetent, competence personified — “competence incarnate,” as...