A book the CNN host co-wrote has received positive reviews and appears to be a sales hit. But it has also generated intense scrutiny of him and his work.

You guys want me to sing, right?” quipped CNN’s Jake Tapper, as he and his co-author Alex Thompson, of Axios, settled into their seats onstage. It was an unusually rock-and-roll setting for a book talk: 9:30 Club is one of Washington’s most storied music halls,