Fifty years ago, when I was born in a summer storm to a widowed mother in a little town in Arkansas, it was unthinkable that I might ever become President. Like other people, I have had crises in my life, personal crises, personal failures, the sense that I had let myself and others down, the sense that maybe I'd never be the person God wanted me to be. He was the first president to represent the baby-boom generation and the last president...