John F. Kennedy came into office wanting to be a transformational president, but he started with three false assumptions: He was convinced that the Third World was about to go Communist, that the Soviets would soon have a nuclear advantage, and that civil rights legislation could wait. When he realized all three were wrong, he was able to course-correct. Obama also came into office wanting to be a transformational leader. He was convinced that as long as Wall Street was sound, the rest of the economy would follow; that as long as he surrounded himself with smart old pros like Larry Summers, he was in good hands; and that bipartisanship was a worthwhile goal unto itself. He was wrong about all three. His response after the Massachusetts defeat shows that he is capable of learning on the job. If he follows through, he still has time to be a transformational president and turn the country around.