But even if the nomination is approved, the spasm of anxiety surrounding it will have highlighted how members of both parties are reassessing their stands on many issues as they try to understand the strain of anger toward the government, Wall Street and other institutions.

In the days since the Democrats lost a crucial Senate seat in Massachusetts, Mr. Obama has struck a tougher tone toward big banks. In the process he signaled a shift away from less aggressive regulatory policies backed by another architect of the bailout, Timothy F. Geithner, the Treasury secretary. On Friday in Ohio, Mr. Obama took a combative approach on health care reform and banking regulation.

But Mr. Obama cannot afford a failed nomination  the Senate has never before rejected a president’s nominee for Fed chairman  and he has publicly and privately backed Mr. Bernanke and Mr. Geithner for their roles in stabilizing the financial system and averting what could have been a wholesale collapse.

Image Opposition to Ben Bernanke has emerged from both the left and the right. Credit... Chris Rank/Bloomberg News

Opposition to Mr. Bernanke has emerged from both the left and the right, as anger has mounted over the Fed’s extraordinary interventions in the market in 2008  which have been lumped together with the huge bailouts of big financial institutions  and over its regulatory failings before the crisis. Mr. Bernanke has also been criticized for backing an easy money policy earlier in the decade that critics say fueled the housing bubble.

“The anger at the Treasury has been spilling over to the Fed,” said Frederic S. Mishkin, a former member of the Fed’s board of governors and a close friend of Mr. Bernanke.

“My view is Chairman Bernanke helped save the world from depression,” said Mr. Mishkin, an economist at Columbia University. “Whether you agree with every policy he’s pursued or some of the ways the bailouts were done, the outcome here, given the severity of the shock, is a good one. But that’s hard to explain to the American public when we’re sitting with 10 percent unemployment.”