Hillary Clinton told CBS News last weekend that she didn’t believe Bill’s affair with Monica Lewinsky involved an “abuse of power.” Ms. Lewinsky, Mrs. Clinton explained, “was an adult.” Progressives and conservatives both cried foul, galled by the hypocrisy espoused by the Democrats’ matron saint: If you’re going to presume every powerful man is de facto guilty of sexual abuse when he makes advances toward a female underling, then surely the most powerful man in the world is guilty of this when he takes up with a 22-year-old intern.

But...