Alyssa Mastromonaco, Deputy Chief of Staff, Operations

In no building is the location of your office more a sign of your influence than in the White House. And in the Obama White House, no one has moved up more than Mastromonaco. In most of the first term, her office was on the ground floor. Then, her title was director of scheduling and advance. But now, in the second term, she has moved upstairs. Her office is right next to the president's study, reflecting her new title as deputy chief of staff for operations. Pete Rouse, counselor to the president, has said that when the president "thinks his life is out of control, or there's too much going on, he calls Alyssa." David Axelrod, the president's longtime aide, says her influence goes well beyond her job title. "A master of logistics, she began as the scheduler in Obama's Senate office and has become the go-to person in the White House for all administrative matters," says Axelrod. Mastromonaco, 37, is a native of the Hudson Valley town of Rhinebeck, N.Y. She attended the University of Vermont before she was bitten by the political bug as an intern to then-Rep. Bernie Sanders, I-Vt. She then transferred to the University of Wisconsin, where she majored in political science. Mastromonaco worked for Obama when he was a senator, played a key scheduling role in the presidential campaign, and has been one of the president's top advisers since.