CLEARWATER, Fla.—Sitting recently on his brick back patio here, Michael Schiavo called Jeb Bush a vindictive, untrustworthy coward. For years, the self-described “average Joe” felt harassed, targeted and tormented by the most important person in the state. “It was a living hell,” he said, “and I blame him.” Michael Schiavo was the husband of Terri Schiavo, the brain-dead woman from the Tampa Bay area who ended up at the center of one of the most contentious, drawn-out conflicts in the history of America’s culture wars. The fight over her death lasted almost a decade. It started as a private legal...