Hillary Clinton, in her memoir, “Living History,” recalled the first words she heard out of Bill Clinton’s mouth. It was the fall of 1970 at Yale Law School, and Bill (she thought that he resembled a Viking) was excitedly telling classmates about the virtues of his home state. “And not only that, we grow the biggest watermelons in the world!” he boasted as Hillary Rodham happened to walk by. Hillary asked a friend who he was. “Oh, that’s Bill Clinton,” the friend told her. “He’s from Arkansas, and that’s all he ever talks about.”