The President will have to act expeditiously to choose Rahm Emanuel's replacement as chief of staff, assuming that Emanuel decides to leave after the November elections to run for mayor of Chicago. Some mid-level White House officials assume that the President has already made up his mind, although he has not indicated his preferences to a wide group of advisers. Deputy National Security Adviser Thomas E. Donilon, currently in China, finds himself at the top of listmakers' lists.

But he may not be at the top of the President's list. One White House adviser who is familiar with personnel matters said that the president has tossed out several other names and is still soliciting advice. Donilon, who has an impressive resume, is not a leading candidate, this person said. Obama, this person predicted, will choose his next chief of staff by setting criteria and then figuring out who best fills them. Priority one is competency, discretion and trust, qualities that Obama believes are linked to each other. Then comes managerial competence, followed by a fresh set of eyes, a deep knowledge of the policy-making process, and perhaps a distinctive voice -- someone who does not have ties to Chicago politics.

Donilon, 54, would nominally fit the bill.

He acts as the chief of operations for the National Security Staff. He manages the interagency working groups that work through tough problems, like Middle East peace, non-proliferation, Chinese currency manipulation, and counter-terrorism. With Vice President Joe Biden, he helped to shepherd the change in mission in Iraq, finding himself in the middle of arcane disputes about Iraqi parliamentary procedure. With Jim Steinberg, the deputy secretary of state, and Larry Summers, the president's chief economic adviser, Donilon has tended to the delicate task of working with China on a long-standing dispute about its currency. More prosaically, when the White House Situation Room receives an alert, Donilon is the staffer who decides how far up the food chain the news should travel.

Donilon is not considered to be a part of the president's inner circle of advisers, but he has distinguished himself, White House associates say, by this work ethic and his accessibility. "When there's a problem, Tom is the first one you want to talk to," a top administration official said.

Donilon has known the Vice President for years, having served on his 1988 campaign staff. Biden "would be thrilled" if he were the chief of staff, an aide said. And just as importantly, he has established a close friendship with Valerie Jarrett, the president's best friend and confidante, whose informal powers complicated her relationship with Emanuel.

But outside of the foreign policy realm, Donilon has less of a footprint. Several senior staff members who work on domestic policy issues said that they barely knew him.

Donilon was once a major force in Democratic politics, having served as a senior adviser to virtually every Democratic presidential ticket since Jimmy Carter's. Donilon's first job in Washington was as an associate liaison to House members during the Carter administration. In 1993, he was named assistant secretary of state for public affairs, having served as Secretary Warren Christopher's chief counsel during the presidential transition, and later as his State Department chief of staff.

In the intervening years, he served as a senior adviser to Biden, worked as a corporate lawyer, and served, like many Democratic poo-bahs of his generation, as an executive at Fannie Mae. Donilon was not implicated in any of the shenanigans that contributed to the mortgage lender's collapse, but he helped with their lobbying strategy, which was quite successful. As a lawyer, his private clients included several firms at the center of the financial crisis, including Citigroup and Goldman Sachs. Optically, this may present problems for a president whose primary job, after a bruising midterm election, will be to kick-start a sluggish economy.

Donilon had made the transition from mere politics to corporate finance and never expected to be on the White House staff. But in 2008, at the urging of his long-tme friend, David Axelrod, and a client, the developer Penny Pritzker, Donilon became an informal adviser to Obama, serving as a sounding board for policy and political ideas and helping the candidate, who was new to Democratic politics, extend his circle of advisers beyond the Chicago suburbs. He helped prepare Obama for his presidential debates, and worked quietly with a team of Obama counselors who were preparing for the transition.

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