A tiny incident in the life of a candidate can sometimes tell us more about him than a dozen speeches or television commercials. When Mitt Romney paused to rub his wife’s aching feet after a tough and tiring day of campaigning in Michigan last fall, we got just a glimmer, but a bright one, of insight into the man who would be president. Mr. Romney, so we’re told over and over, is a stuffed shirt who doesn’t smoke or drink and lacks quotable spontaneity. He should loosen up. Well, it’s time to talk about his warmer qualities.