Dan Pfeiffer, Assistant to the President; Senior Adviser

When Pfeiffer started working for Obama, he was pretty lonely. It was Martin Luther King Day in 2007. There were only a few in this town who thought the freshman senator from Illinois had a chance to win the presidency. But Pfeiffer believed back on that day when he helped open a small office on Connecticut Avenue, quickly discovering the place didn't even have Internet service yet. Pfeiffer was there the day they connected the Internet; he was there the day Obama won the election; he was there the day Obama was inaugurated. And, while most of the others who were with him that day in 2007 have moved on, Pfeiffer, now 37, is still here. Indeed, that is one of Pfeiffer's secrets. He can be counted on to always be there. After a grueling first year in the White House, he volunteered to hold down the fort in August even though he had not had a vacation in almost three years. Even now, just about Pfeiffer's only breaks come when he slips away to cheer for the Hoyas of his alma mater, Georgetown University. His enthusiasm comes in part from what Obama told his senior staff when he knew many were considering moving on. "He said we'll never have a better opportunity in our lives to do more good for more people than over the next four years," Pfeiffer often quotes the president as saying. For Pfeiffer, the second term brings a new title. After serving as communications director in the first term, he has taken David Plouffe's job as senior adviser where, longtime aide David Axelrod says, he does "strategic thinking for message operation."