As the ongoing David Letterman sex/blackmail scandal has unfolded a couple of things have gone through my mind. The first was a sense of relief that Letterman would no longer resort to any more Clinton jokes, which he seemed to have been doing as recently as just the other day. The other was more elusive. The whole story reminded me of something. Not just the recent incident but the other bizarre things that have beleaguered Letterman -- the crazy woman stalker, the plot to kidnap his child. Then it hit me: Martin Scorsese's "The King of Comedy." It's all there -- the stalking, the kidnapping, the sex (or whatever it is that Sandra Bernhard is doing to Jerry Lewis as he's encased in duct tape), the extortion. The biggest difference being that the movie has a poignant innocence beneath its sordness. Poor Rupert Pupkin just had a dream. He wanted to triumph at what he loved doing. He wanted to make the world laugh. He wasn't in it for the money. Maybe that's the difference between the movies and TV.