By PATRICIA COHENPublished: February 19, 2008Shannon Neal can instantly tell you the best night of her life: Tuesday, Dec. 23, 2003, the Hinsdale Academy debutante ball. Her father, Steven Neal, a 54-year-old political columnist for The Chicago Sun-Times, was in his tux, white gloves and tie. “My dad walked me down and took a little bow,” she said, and then the two of them goofed it up on the dance floor as they laughed and laughed.A few weeks later, Mr. Neal parked his car in his garage, turned on the motor and waited until carbon monoxide filled the enclosed space and took his breath, and his life, away.Later, his wife, Susan, would recall that he had just finished a new book, his seventh, and that “it took a lot out of him.” His medication was also taking a toll, putting him in the hospital...