She's back.  Molly Ivins, our most perceptive, outrageously funny political commentator, has given us an uproarious new book. In , Ivins proved that no one has a steadier gaze or a quicker trigger finger, as she hits the bull's-eye in such targets as George Bush, Bill Clinton, Camille Paglia, the Clarence Thomas hearings, and the ethics-twisting, English-slaughtering pols of her beloved Texas.  Here's Molly on: The 1992 Republican Convention: "Many people did not care for Pat Buchanan's speech; it probably sounded better in the original German." Texas politics: "Better than the zoo, better than the circus, rougher than football, and even more aesthetically satisfying than baseball." Gibber Lewis, former House Speaker of the Texas State Legislature: "He once announced, 'This is unparalyzed in the state's history." Another Gibberism: "It could have bad ramifistations in the hilterlands."