Updated 5:06 p.m. Eastern Time
Independent Connecticut Sen. Joe Lieberman said Friday that he is "confident" that there are now enough votes in the Senate to repeal the military's "don't ask, don't tell" policy and send a repeal bill to the president to sign. The vote could come as early as tomorrow.
Supporters of repeal havea measure that would allow repeal the 1993 policy banning gay men and women from serving openly in the military, but both times they fell short of the 60 votes needed to overcome a Republican-led filibuster.
Many Republicans who said they were sympathetic to repeal said they voted no because of procedural concerns about the way Democrats introduced the measure, which was actually a Defense authorization bill with the "don't ask, don't tell" repeal attached.
In the wake of those defeats, supporters in both the House and Senate introduced a standalone repeal bill. That bill, and the Senate is .
Backers of repeal see this weekend's vote as the last, best chance to repeal the policy before a more Republican Congress takes over in January.
Here's how the Senate gets to 60 votes: There are 58 senators who caucus with Democrats, and all but West Virginia's Joe Manchin and potentially North Dakota's Kent Conrad appear poised to back the bill.
That makes 56 votes. There are at least four Republicans who say they will vote for repeal: Susan Collins and Olympia Snowe of Maine, Scott Brown of Massachusetts, and Lisa Murkowski of Alaska. In addition, Dick Lugar of Indiana and George Voinovich of Ohio are considering voting for repeal. That adds up to 60 to 62 votes, and more Republicans could peel off and back the bill if repeal seems inevitable.
"I continue to believe that we are going to end up with more support on the Republican side than the four that we've talked about and that is very encouraging," Lieberman said Friday.
(One side note: Democratic Sen. Ron Wyden of Oregon will undergo prostate surgery on Monday. But his office says he will be in the Senate for the votes over the weekend.)
As Lieberman acknowledged Friday, a "surprise" development could still derail the bill. One possibility would be for Republicans to abandon their support for reasons similar to those that sank the effort last time around, the procedure for introducing amendments to the measure.
Yet he expressed optimism that the bill was on its way to passage during the lame-duck session.
"I don't think it's going to be credible for anybody to say for a technical procedural reason, even though I support the principle, I'm not going to vote for it," he said.
If the bill to repeal DADT passes in its current form, it will still be quite some time before gays can serve openly in the military.
First the president must sign the bill and he and military leaders must certify a Pentagon report that found that while there are short-term challenges to repealing the policy, there would be minimal overall risk to military effectiveness if it were to be repealed. That's the easy part. Then the Pentagon would begin an implementation plan, which consists of training troops and rewriting all the policies and regulations that would be affected.
Taking the necessary time to institute the policy correctly has been one of Defense Secretary Robert Gates' strongest arguments for legislative repeal: If the matter is left to the courts and they mandate an immediate repeal, he has suggested, the military will not have sufficient time to properly implement the policy change.
The Pentagon is being deliberately vague about how long the entire procedure would take, but at one point Gates said it could take up to a year.
No gays have been discharged since procedures were changed in October to require each discharge to be personally approved by the civilian head of whatever service the service-member belongs to.
In terms of what to expect Saturday: There are two votes scheduled in the Senate, on cloture (to cut off debate) for "Don't Ask, Don't Tell" and the DREAM Act. The votes may begin around 10 am. If "Don't Ask" gets 60 votes for cloture, a 30-hour debate clock begins before a final vote.
That would set the final vote for Sunday -- though lawmakers could agree to give up that time and just get on with the final vote tomorrow afternoon or evening. They could also kick the final vote to Monday to avoid having to work on Sunday.
Brian Montopoli is senior political reporter for CBSNews.com. You can read more of his posts here. Follow Hotsheet on Facebook and Twitter.