In 1987, Gary Hart--articulate, dashing, refreshingly progressive--seemed a shoo-in for the Democratic nomination for president and led George H. W. Bush comfortably in the polls. And then: rumors of marital infidelity, an indelible photo of Hart and a model snapped near a fatefully named yacht (Monkey Business), and it all came crashing down in a blaze of flashbulbs, the birth of 24-hour news cycles, tabloid speculation, and late-night farce. Matt Bai shows how the Hart affair marked a crucial ...