When discussing foreign policy, Obama said this: "We are the party of Roosevelt. We are the party of Kennedy. So don't tell me that Democrats won't defend this country." It's been more than 40 years since John F. Kennedy was president. Since then, three other Democrats have held the office: Lyndon Johnson, Jimmy Carter, and Bill Clinton. Why didn't Obama mention them? Is this a tacit acknowledgment that the foreign policies of those presidents were, to put it charitably, a mixed bag?