Sen. Joe Lieberman (ID-Conn.) told his Democratic colleagues nearly a year ago that they would “not regret— letting him keep his chairmanship of the Homeland Security and Governmental Affairs Committee.

But after Lieberman signaled Tuesday his willingness to filibuster the Democrats’ top legislative priority this year — health care reform — leaders may feel the need to remind him of his own words in order to avoid another vote on punishing one of their own.

“We have a long ways to go before we get there,— Senate Democratic Steering and Outreach Committee Chairwoman Debbie Stabenow (Mich.) said. “We’re working through all those details. … I’m optimistic that we will not be in that position.—

But White House spokesman Robert Gibbs issued what appeared to be a veiled threat when told of Lieberman’s position. After all, it was President Barack Obama who came to Lieberman’s defense last fall when, after Lieberman spent a year campaigning for then-presidential hopeful Sen. John McCain (R-Ariz.), the Democratic Conference considered stripping him of his gavel.

“I think Democrats and Republicans alike will be held accountable by their constituents who want to see health care reform enacted this year,— Gibbs said. “And we know that if that doesn’t happen, people say they’ll be very disappointed by that, and we think people will make progress to ensure that this gets done.—

Still, Lieberman appeared to box himself in Tuesday, unlike a handful of other Democratic centrists who have expressed skepticism about voting for the bill but have stopped short of saying they would block the bill from passing.

Though Lieberman said he would vote for cloture to allow the Senate to officially begin debate on the health care overhaul, he said he is prepared to support a Republican filibuster of the measure if it includes Senate Majority Leader Harry Reid’s (D-Nev.) plan to create a public insurance option.

[IMGCAP(1)]“I’m inclined to vote for cloture on the motion to proceed to a debate on health care reform because I believe we need to have a debate on health care reform, and I hope to be in a position to vote yes on health care reform,— Lieberman told reporters Tuesday. “But I’ve also said that if the current proposal remains as it is, unamended before the final vote on the floor, that I will not vote for cloture because I don’t support a government-operated health insurance company that will end up costing taxpayers a lot of money.—

Lieberman said he would even vote to filibuster a bill with a proposal by GOP Sen. Olympia Snowe (Maine) to allow for a public insurance option as a fallback if private insurers do not lower costs and increase coverage on their own. That option had been favored by the Obama administration because it was seen as a way to entice Senate Democratic centrists to vote for the bill as well as a way to declare the bill bipartisan.

Because 60 votes are needed to beat back a filibuster and invoke cloture, Reid needs the support of all 60 Members of the Democratic Conference, because Republicans are unanimously opposed.

Asked why he was not heeding the call of Democratic leadership to at least vote with the Conference on procedural matters, Lieberman said, “Because that is not using the rights that I have as a Senator under the rules of the Senate to stop something from happening that I think will be bad.—

Still, some Democrats expressed hope that Lieberman would change his mind.

“If any Democratic Senators are drawing lines in the sand, we hope they will erase it and start over,— Sen. Bob Casey (D-Pa.) said when asked about Lieberman’s remarks.

One senior Senate Democratic aide said it was puzzling that Lieberman would make comments leaving him so little wiggle room but said it may be a bluff.

“There’s going to be a lot of posturing between now and the end of this process,— the aide said. “So to focus on what one person says on any given day when we don’t have a bill yet would be premature.—

But other Democrats said Lieberman’s disloyalty to the party should not surprise anyone. Lieberman has been a reliable vote on many Democratic priorities but has regularly sided with Republicans on defense issues. He was one of the Bush administration’s most vocal allies in the war in Iraq and has sided with Republicans in calling for Obama to add more troops in Afghanistan.

“Lieberman is not just undermining the Democratic caucus but is also clearly doing the bidding of all the insurance companies he is cozy with,— another senior Democratic aide said.

Shortly after Obama won the election in November, Lieberman nearly lost his chairmanship in retaliation for his support of McCain and did lose a prime slot on the Environment and Public Works Committee.

Before the Democratic caucus voted on his fate, Lieberman not only told his colleagues that they would “not regret— keeping him in the fold, he also told leaders he would vote with them on major procedural votes — i.e., he would not filibuster key Democratic agenda items.

“Joe Lieberman votes with me a lot more than a lot of my Senators. He didn’t support us on military stuff and he didn’t support us on Iraq stuff. But you look at his record, it’s pretty good,— Reid told reporters after the vote.

Sen. Frank Lautenberg (D-N.J.) was more explicit about what was expected of Lieberman going forward,

“We obviously expect his full support for the Democratic agenda,— Lautenberg said last year.

Lieberman’s falling out with the party began in 2006 when he lost his Democratic primary bid over his support for the war in Iraq. He won the general election, however, as a self-described Independent Democrat but returned to the Senate with bruised relationships with many of his fellow Democrats.

Lieberman said Tuesday that he is not worried that liberals will again call for his chairmanship or membership in the caucus to be revoked.

“You know, I’m at a point in my public service career that I’m just going to do what I think is right and makes sense,— Lieberman said, adding that he hadn’t heard any grumbling from his colleagues. “Nobody has said anything to that effect. I leave it to my colleagues to decide.—

Reid brushed off talk of Lieberman’s declaration on the health care package.

“I don’t have anyone that I have worked harder with, have more respect for in the Senate than Joe Lieberman,— Reid said Tuesday. “Sen. Lieberman will let us get on the bill, and he’ll be involved in the amendment process. … But Joe Lieberman is the least of Harry Reid’s problems.—