Readers and political junkies of a certain age undoubtedly remember the lurid details of the sex scandal that ended presidential candidate Gary Hart’s political career almost thirty years ago. So what’s left to know? That was my reaction until I read All the Truth is Out (Knopf, $26.95), the fascinating new book by Matt Bai, the national political columnist for Yahoo News and formerly of The New York Times Magazine. Bai conducted lengthy interviews with all of the major characters involved in the scandal (including the leading journalists) and his book raises important questions about when and whether indiscretions by politicians constitute newsworthy character lapses that disqualify them from political office. Told in a breezy narrative, Bai’s story also corrects some widely held misconceptions about the events that led to Hart’s political collapse. This is a smart, compassionate, and eloquent book about our evolving political and journalistic culture.