David Brock and Ari Rabin-Havt examined the career of Roger Ailes, president of Fox News. The authors contend that Mr. Ailes, a former media consultant for Richard Nixon, Ronald Reagan, and George W. Bush, brought a conservative political agenda to Fox News when he was hired in 1996. The authors argue that Mr. Ailes turned the network into an extension of the Republican Party. They responded to questions from members of the audience at Politics & Prose Bookstore in Washington, D.C.