Jim Lehrer will no longer be the main face of PBS' "NewsHour." He was the show's anchor for 36 years, but there has not been a lot of fanfare around his departure. "I didn't want to make a big to-do about it," he says. He reflects on reporting on the Kennedy assassination and what he has learned about politics and history. His new book, "Tension City: Inside the Presidential Debates, from Kennedy-Nixon to Obama-McCain" comes out in the Fall; he will continue moderating Shields and Brooks on Fridays. So what's next? "I want to write better books," Lehrer tells us.