few days before Christmas, the mood in Representative Darrell Issa's office was jovial. Outside, the hallways were filled with the House's equivalent of scalps: wooden pallets piled high with shrink-wrapped boxes belonging to defeated or retiring Democrats. Inside, some of Issa's closest advisers sat around talking trash. Issa, a six-term California Republican, had recently been elected chairman of the House Committee on Oversight and Government Reform, which, according to House rules, “may at any time conduct investigations of any matter.” Now that he had been given the power to subpoena, investigate, and harass the Obama Administration, Issa was being described as a future leader of his party—and the man most likely to weaken the President before the 2012 election.