But the legislation stalled when Democrats lost a U.S. Senate seat in Massachusetts last month, depriving them of the 60 seats needed to overcome Republican procedural blocking.
The White House plans to set up the commission by executive order after it failed to pass the Senate last week. But Republicans say it would merely give Democrats political cover to sign off on tax hikes, and their cooperation is in doubt.
Even if all goes according to plan, the White House still forecasts U.S. public debt rising above 71 percent of GDP by 2013, up from 53 percent in 2009 -- levels that could spook investors and drive up the government's borrowing costs.
The flurry of hearings inspired a round of finger-pointing on Capitol Hill. Republicans blamed Democrats' aggressive spending measures to boost the economy, while Democrats said policies pursued by former Republican President George W. Bush -- cutting taxes while pursuing two wars and setting up a prescription-drug benefit -- were largely to blame.
"Saying that this is the responsibility of the (Obama) administration or the Democratic Congress is like a guy who ran up a credit card bill and left before the credit card bill arrived in the mailbox," Orszag said.
(Additional reporting by John Whitesides, Glenn Somerville, Susan Cornwell, Steve Holland, and Caren Bohan; Editing by David Storey)