Filling the void

Geithner was instrumental in helping Republican President George W. Bush and then Obama fight the 2007-09 credit crisis, first as the president of the New York Federal Reserve Bank and then as Obama's only Treasury secretary.

He survived calls for his resignation over how the Treasury handled the $700 billion Troubled Asset Relief Program bank bailout fund. He fought with Republican lawmakers over raising the debt ceiling in 2011.

As he tried to resign, Obama asked him to stay through the November presidential election.

Obama's chief of staff, Jack Lew, is widely expected to be chosen to replace Geithner. But a number of key Republicans do not like working with Lew, the former budget director, which could potentially exacerbate the raw relations between the administration and Congress.

"Geithner's leadership and expertise would undoubtedly be a tremendous asset to the president and the country as we confront this next challenge," said Max Baucus, the Democratic chairman of the Senate Finance Committee, which is in charge of vetting the next treasury secretary.

It is not clear who Obama would choose to lead negotiations for the next set of fiscal deadlines. Vice-President Joe Biden, who helped broker the fiscal cliff deal, or Rob Nabors, the White House's main liaison to Congress, could fit that bill.

"That is a lot of experience and steadiness that you would be getting rid of," said Steve Bell, a former Senate budget committee staff director who is now an economic policy director with the Bipartisan Policy Center.