The fox knows many things, but the hedgehog knows one big thing.—Archilochus (7th-century BC) Mark Penn might not be appearing before the cameras on Hillary's behalf nowadays, but bet that he is beavering away behind the scenes on his polling. And judging from Hillary's dogged [to mix an animal metaphor] performance on this morning's Today, it's obvious that Penn's turned up one big thing: Dem primary voters hate oil companies. Meredith Vieira gamely tried to get Clinton onto other subjects during her interview. But no matter the question, the answer was almost invariably the same: I Hate Big Oil. Since...