President Obama held his year-end press conference today, and the tone got set with the very first question, from AP reporter Julie Pace: All things considered, "has this been the worst year of your presidency?" The president laughed and said, "That's not how I think about it." He acknowledged "frustrations" but also sought to pin some of the blame on Congress. Later, however, he cited the ObamaCare rollout when asked directly to name his biggest mistake of the year. “Since I’m in charge, obviously we screwed it up,” the president said. “I promise you, I probably beat myself up even worse than you or Ed Henry does on any given day," he said to ABC's Jon Karl, as noted by the New York Times.