What's old is new again. Jay Leno made a surprise visit to "The Tonight Show" on Tuesday night, stepping in to deliver the monologue when his injury-prone successor, Jimmy Fallon, "pulled a muscle" during a joke about Sen. Bernie Sanders. (We all know how dangerous those can be.) Like many a retired talk show host before him, Leno, who just so happens to have a show premiering Wednesday on CNBC, was sporting a new look: longer hair and a trendy all-black ensemble. The jokes, however, were more familiar, taking aim at the Kardashians, the Clintons and the Bushes. The more things change, the more they stay the same.