A Reuters poll showed 35 senators were either committed to approving the nomination or leaning that way, while 17 were outright opposed or inclined that way. Senate leaders need to secure a super-majority of 60 votes in the 100-member chamber to overcome efforts by some senators to block the nomination.
Senate Majority Leader Harry Reid expects a confirmation vote by the end of this week and hopes to have the necessary 50 votes to support reappointment, his spokesman said.
What looked like a sure thing one week ago was thrown into doubt when a handful of lawmakers, including two Senate Democrats said on Friday they would not support Bernanke because of his handling of Wall Street bailouts.
Senator John McCain, the Republican presidential candidate in 2008, said he would vote against the nomination because Bernanke must be held accountable for many of the decisions that contributed to our financial meltdown.
Bernanke's first four-year term as chairman expires on Sunday. If he is not confirmed, the Fed's vice chairman, Donald Kohn, is poised to take over on an acting basis.
The Fed has become a prime target of public outrage as the U.S. unemployment rate has hit 10 percent while Wall Street profits -- and bonuses -- soared. Many voters saw that as evidence of an economic policy that favored Wall Street over Main Street.
That anger was on full display last week when voters handed Democrats an embarrassing defeat in a special Senate election in Massachusetts, which had been a Democratic stronghold for decades. That left Democrats one vote short of the 60 needed to clear Republican legislative roadblocks.
President Barack Obama has responded by taking a tougher tone with Wall Street and stepping up his commitment to create jobs. On Monday, he proposed new initiatives aimed at helping middle-class families.
Obama contacted the Democratic Senate leadership on Saturday and the White House dispatched advisers to the Sunday talk shows to muster support for Bernanke.
Chris Krueger, a policy analyst with Concept Capital in Washington, said the White House appears to have applied a sufficient tourniquet to Bernanke's reconfirmation. Krueger now sees a 70 percent chance that Bernanke will win confirmation, up from 55 percent on Friday.
That the vote was even in doubt was surprising, and the uncertainty sent stock markets down sharply on Friday, although they recovered on Monday as Bernanke's approval looked more certain.
This was not akin to squeezing 60 votes for healthcare, or getting a controversial judge through a confirmation. This was reconfirming Time's Man of the Year, which was a slam dunk before last Tuesday, Krueger said.
OBAMA ALLY OPPOSES NOMINATION
Bernanke, a Republican who was appointed by former President George W. Bush to succeed Alan Greenspan as Fed chairman in 2006, has received widespread praise for his response to the financial upheaval, which began with failing U.S. mortgage loans but rapidly expanded into a global crisis.
He improvised to come up with special lending programs that many economists think helped prevent the recession from becoming a depression.
But Bernanke has also been blamed for missing the warning signs of a dangerous bubble forming in the housing market and underestimating its power to wreak havoc on the economy.
MoveOn.org, a Democratic political advocacy group and a strong supporter of Obama's 2008 presidential election, urged its members to tell their senators to vote against Bernanke.
Bernanke presided over the biggest Wall Street bailout in history, making trillions of dollars in loans to big banks with no oversight, the group said. But after taking extreme measures to save the banks, Bernanke has shown no interest in helping regular folks who can't find jobs, even though ensuring 'full employment' is explicitly part of his mandate.
But many investors see Bernanke as a known entity who is committed to keeping short-term interest rates low until the economy strengthens. They see the reappointment fight as a worrisome sign of politics interfering with monetary policy.
The backlash over the financial crisis and ensuing government bailouts has put the U.S. central bank under intense political scrutiny. The House of Representatives last month approved a measure that would give Congress authority to audit the Fed's interest rate decisions, the very heart of the central bank's monetary policy, and the Senate is considering whether to strip the Fed of its bank regulatory authority.
(Editing by Kenneth Barry)