Some of the critics’ complaints had merit, said the committee chairman, Senator Christopher J. Dodd of Connecticut. Still, Mr. Dodd added, “Chairman Bernanke must also receive credit for the critical role he played in the events of last fall.” Had he and others not acted, Mr. Dodd said, the nation probably would have faced “utter economic catastrophe  and I believe nothing short of that was at risk.”

Instead, Mr. Dodd added, “I believe better days do lie ahead.”

A Republican, Senator Judd Gregg of New Hampshire, offered a strong endorsement of the nominee. While “mistakes were made” under his purview, Mr. Gregg said, Mr. Bernanke’s swift reaction to the financial crisis had proved crucial. “I tell you, it worked,” he said. “It’s that simple.”

But Senator Bernard Sanders, independent of Vermont, strongly opposes Mr. Bernanke’s nomination because of his role in the bailouts and has put a hold on the nomination. That means it will require 60 votes, not a simple majority.

Although his confirmation appears likely, a number of no votes are expected from members of both parties when the full Senate votes and if Mr. Bernanke is not confirmed by Jan. 31, when his term ends, then the Fed’s vice chairman, Donald L. Kohn, would temporarily take over.

President Obama, in announcing his nomination of Mr. Bernanke in August, said he had led the Fed through “one of the worst financial crises that this nation and this world have ever faced” and, because of his background, his expertise on the Depression and his unflappable personality, was ideally suited to help lead the recovery.

During his four years, Mr. Bernanke has emerged as a favorite target of liberals and conservatives alike. Critics have tried to portray him as cozy with Wall Street elites and slow to react to signs that the financial system was on the brink of collapse.

Mr. Bernanke, a former professor at Princeton, was initially criticized as too academic, but he has since spearheaded some of the most interventionist actions by the Fed in its history.