It's not the primaries. Moderator Jim Lehrer of PBS just told the audience that there will be absolutely no applause and no booing.
Jim Lehrer tells debate audience if they hear something they don't like, they are to "sit on it!
— Sarah Huisenga (@SarahH_CBSNJ) October 4, 2012
It's Lehrer's 12th presidential debate; in an interview with The Post he compared the experience to “a walk down a knife blade.”