Donohue called Lew a "skilled operative," a "vigorous and strong person," and a "tough dude."
Rob Nichols, the president and CEO of the Financial Services Forum, a major banking industry group, said: "Given his experience in the government and private sector, Mr. Lew is well-suited for the job especially at a time when Washington must come together to address our debt situation and put our nation on a long-term fiscally sustainable path."
Lew's nomination is the fourth major personnel change in the administration since Obama's re-election. Obama tapped Sen. John Kerry, D-Mass., for the State Department, Hagel to lead the Pentagon and White House counterterrorism adviser John Brennan for the CIA's top job.
Lew was a top aide in the 1980s to O'Neill, a Massachusetts Democrat, playing a role in the Social Security deal between the speaker and President Ronald Reagan in 1983.
Before becoming Obama's chief of staff, Lew was director of the Office of Management and Budget, a post he also held in the Clinton administration, serving from 1998 to early 2001. While running OMB during the Clinton administration, Lew helped negotiate a balanced budget agreement with Congress, something that has eluded Washington ever since.
But while the bulk of his experience is in Washington, Lew also worked on Wall Street as managing director and chief operating officer of Citi Global Wealth Management and then Citi Alternative Investments. At the start of the Obama administration, he oversaw international economic issues at the State Department.
Despite his stint on Wall Street, Lew doesn't have the type of experience that Geithner brought to the job at the height of the financial crisis in 2009. Indeed, there's not as much of a premium on those skills now as the nation's attention has turned from bank bailouts to fiscal confrontations and brinkmanship.
"The basic financial position and economic position of the country is much stronger today that it was four years ago," said Michael Barr, who was assistant treasury secretary for financial institutions in 2009 and 2010. "That's a significant advantage for a treasury secretary coming in."