Sen. Joe Lieberman (ID-Conn.) privately assured President Barack Obama and members of the Senate Democratic Conference on Tuesday that he would likely support the chambers health care reform bill when it comes to a vote.Speaking during a full Democratic caucus meeting with the president, Lieberman said he has not enjoyed being on the opposing side during the health care debate, but Senate Democratic leaders decision to eliminate both a public insurance option and a Medicare expansion from the bill would probably be enough to secure his vote, according to a Senate Democratic source.Lieberman told the president and his fellow Senate Democrats, From everything Im hearing and everything Im learning, I think this is something I can support, the source said.Lieberman did leave himself some wiggle room, however, telling Members that he would not make a final decision until he has seen a Congressional Budget Office cost estimate and has read the final language in the bill. That CBO report could come Tuesday evening.Lieberman has threatened to filibuster the health care bill twice over the public option and a proposed compromise plan that would have allowed seniors age 55 to 64 to buy into Medicare. Facing unanimous Republican opposition to the bill, Senate Democratic leaders need all members of the Democratic Conference, including Lieberman, to vote with them in order to secure the 60 votes needed to beat back a GOP-led filibuster. Obamas comments at the Tuesday meeting appeared intended to push liberals to accept Liebermans and other centrists demands to drop major government programs, such as the public option and the Medicare expansion. Ideological purity cannot get in the way, Obama said, according to one Senate source.Obama also appeared to acknowledge that a public option is now off the table, telling Members that the bill remained a strong, positive piece of legislation without that provision. He also said they should not underestimate the ability of a government-sponsored health insurance exchange to create the kind of choice and competition that a public option was intended to achieve, the source said.Most progressive Senators have said they accept that they are unlikely to secure passage of a bill with a public option, but there are still a handful of freshman liberals who have been agitating over the decision to eliminate both the public plan and the Medicare compromise.