There are only two truly revealing sentences in Zev Chafets’s new biography of Roger Ailes, the founder of Fox News and message minder for a host of Republican presidents. They serve as bookends of sorts. The first, in the preface, informs us that the project at hand will be superannuated: “He intends to write an autobiography someday, and I imagine he is holding something in reserve.” The second appears 249 pages later, in the acknowledgments: “I am indebted to Brian Lewis, Fox News executive vice president for corporate communications, who was always willing to answer just one more question.”