Hillary Clinton’s performance at the Unity rally was astounding. To my ear, it wasn’t a great speech, or especially well delivered. But it wasn’t at all hesitant. There she was, helping her bitter rival gain the prize she has long dreamed of and now can (almost surely) never have. And she did it with a smile: not a tight, controlled grimace, but a smile of apparent warmth and sincerity. Ask yourself: In a comparable situation in your own life, could you do as well? I know I couldn’t.