Obama's decision could tie the hands of Senate Majority Leader Harry Reid, who has been negotiating to remove Lieberman as chair of the Homeland Security and Government Reform committee while keeping him within the caucus. Lieberman has insisted that he will split from the Democrats if his homeland security position is stripped.
Aides to the president-elect did not return requests for comment. Senate officials were unclear whether Obama would be comfortable with Lieberman maintaining his current committee post.
Meanwhile, Senate Minority Leader Mitch McConnell has said that he would welcome Lieberman into the GOP, though he has little to offer in terms of committee assignments.
If Lieberman were to continue caucusing with the Democrats without being punished for his campaign conduct -- Democrats say he broke a promise not to campaign negatively against Obama -- the progressive community will undoubtedly be up in arms. For Obama, however, the move may be a shrewd gesture towards reconciliation, in the process taking a potentially taxing political fight off the table.
Fellow Connecticut Senate Chris Dodd, who has spoken out in favor of Lieberman remaining in the party, explained as much to reporters on Friday:
"What does Barack Obama want?... He's talked about reconciliation, healing, bringing people together. I don't think he'd necessarily want to spend the first month of this president-elect period, this transition period, talking about a Senate seat, particularly if someone is willing to come forward and is willing to be a member of your family in the caucus in that sense."
A Democrat close to Lieberman, meanwhile, said he thought that keeping Lieberman in the fold "would be a good move for Obama as a way to make real his promise of new politics, a less partisan Washington and more unity. He would do so at some risk. Obviously there is a liberal wing of the party that wants Joe punished... "
There is, perhaps, one measure by which Democratic leadership can still reconcile the competing realities of Lieberman's future in the caucus. One Democratic aide said that the party was considering letting the Connecticut Senator keep his post at homeland security but forcing him to relinquish one or both of his spots on two more high-profile committees: Armed Services and Environment & Public Works.
Lieberman is in line for leadership roles in both of those committees should the current chairs leave their posts. On Armed Services, the two senators ahead of him are Ted Kennedy and Robert Byrd. On Environment and Public Works, current chair Barbara Boxer may face a tough reelection campaign in 2010 and second in line, Sen. Max Baucus, already heads another committee.
If Democratic leadership were to keep Lieberman on homeland security but impede any chance of ascending to these other posts, that may be enough to placate progressive activists demanding punishment while keeping the Connecticut Senator in the caucus.
UPDATE: Josh Marshall at Talking Points Memo writes that Bill Clinton has also been "making calls on Sen. Lieberman's behalf," something that the Huffington Post later heard from another Hill source.
But Matt McKenna, a spokesman for the former president, vehemently denies the report.
"It's completely false," he says.