“The president probably took David’s opinion with more certitude than he did anybody else’s,” said William M. Daley, who left as chief of staff last month after a year in the White House. “If David said X, I think the president would more often believe X than challenge it.” Mr. Daley added that Mr. Obama would be more likely to heed Mr. Plouffe’s advice than his or that of other longtime confidants, the senior advisers Valerie Jarrett and Pete Rouse.

Mr. Plouffe’s history with the president ensures him a rarified place in any Obama endeavor. He became a folk hero within the grass-roots network in 2008, his sleep-deprived face and deadpan delivery evoking urgency (and twiggy frame crying out for cheeseburgers). Mr. Plouffe approaches campaigns with a tribal sense of good-vs.-evil, rarely seeing much humanity in opponents. (He assumed that Hillary Rodham Clinton’s crying episode before the New Hampshire primary in 2008 was “deviously contrived and staged,” he wrote in his campaign memoir, “The Audacity to Win.”)

In keeping with the high-minded rhetoric of 2008, Mr. Plouffe railed against the corrosive political culture in Washington, even though he has worked there for years. Mr. Obama himself would talk about those who entered politics for “the right reasons” and those who wanted to make money. And Mr. Plouffe, in his memoir, denigrated Republicans as “a party led by people who foment anger and controversy to make a name for themselves and to make a buck.”

Image David Plouffe “is the one most in tune with the president's personality,” a colleague says. Credit... Doug Mills/The New York Times

After Mr. Plouffe made a name for himself in the campaign, he made a buck. He signed on with the Washington lawyer Robert Barnett, a longtime Clinton loyalist whom Mr. Plouffe had privately denigrated during the campaign as a consummate Washington insider, according to several campaign aides.

Considered the prime facilitator in Washington for those seeking to “monetize” their political service, Mr. Barnett negotiated a reported seven-figure book advance for Mr. Plouffe and set him up for speaking gigs. Mr. Plouffe earned $1.5 million in 2010, according to White House disclosure statements, which included management consulting work for Boeing and General Electric, and close to $500,000 for speeches around the world, including $100,000 from MTN Nigeria, an African telecommunications firm.

In early 2009, Mr. Plouffe agreed to speak in Baku, the capital of Azerbaijan, for $50,000 without realizing that the event’s sponsor had ties to the authoritarian government there. After complaints from human rights groups, Mr. Plouffe donated his fee to the National Democratic Institute, a pro-democracy nonprofit organization partly financed by the American government.