Representative Dennis Kucinich, one of the most liberal members of Congress and a supporter of nationalized healthcare, became the first Democrat in the House of Representatives to switch from no to yes on the overhaul as it neared a likely final vote on Sunday.

This is a defining moment for whether or not we'll have any opportunity to move off square one on healthcare, Kucinich said in announcing his switch two days after Obama lobbied him on an Air Force One flight to Kucinich's home state of Ohio.

The leaders of Catholic religious orders representing about 59,000 nuns urged Congress to pass the Senate healthcare bill, which has been strongly opposed by the Conference of Catholic Bishops for not sufficiently restricting abortion coverage.

Despite false claims to the contrary, the Senate bill will not provide taxpayer funding for elective abortions, a letter to lawmakers said. This is the real pro-life stance, and we as Catholics are all for it.

The new support was a boost for Democratic leaders struggling to finish work on a final package of changes to the Senate's version of healthcare reform and line up the 216 House votes needed to pass it.

Democratic leaders, who met late into Wednesday night on the changes, said the final version and cost estimates from the Congressional Budget Office would not be made public until Thursday.

House leaders have promised to post the final bill on the Internet for at least 72 hours before voting, meaning the earliest it could hit the House floor would be Sunday.

Democratic leaders were struggling to craft a package that would meet deficit reduction targets and withstand challenges by Republican opponents in the Senate.

Kucinich, who voted against the reform bill for not being liberal enough when the House approved its version in November, said the weekend vote on the Senate's version of the bill would be very close.

Even though I don't like the bill, I've made a decision to support it in the hope that we can move to a more comprehensive approach once this legislation is done, he told reporters.

Kucinich is the first of 37 House Democrats who voted against the overhaul in November to flip to the yes column, but Obama and House leaders are frantically searching for more as they try to round up the 216 votes needed for passage.

'A GOOD SIGN'

That's a good sign, Obama told reporters in the Oval Office. Asked what he had told Kucinich, Obama said, I told him 'thank you.'

Kucinich, a former presidential candidate known for his strong liberal views, might not bring a lot of followers with him as most of the Democratic opposition came from moderates.

But the letter from the Catholic nuns could help reel in some of about a dozen anti-abortion rights House Democrats who have threatened to switch to no on the Senate bill because they say its ban on the use of federal funds for abortions is not strong enough.

Democratic Representative Dale Kildee, a staunch abortion rights opponent who voted for the House bill in November but was considered a possible no on the Senate bill, said he was satisfied the Senate's provision on abortion met his concerns.

Voting for this bill in no way diminishes my pro-life voting record or undermines my beliefs, Kildee said in a statement.

About three dozen undeclared Democrats could decide the overhaul's fate and end a political brawl that has consumed the U.S. Congress for months and put a dent in Obama's personal approval ratings.

I sense a sea change where people are trying to find a way to vote yes, Democratic Representative Robert Andrews said.

The overhaul would extend coverage to more than 30 million uninsured Americans and ban insurance practices like refusing coverage to those with pre-existing medical conditions.

Health insurer shares were mixed on Wednesday while the broader market rose slightly. The Morgan Stanley Healthcare Payor index was up 0.5 percent and the S&P Managed Health Care index dropped 0.4 percent.

Under the procedure planned for passing the overhaul, the House would vote this weekend on whether to approve the Senate's bill. The changes sought by Obama and House Democrats would move in a second separate bill.

Republicans have criticized Democrats for considering using a complicated process to avoid a direct vote on the Senate-passed bill, which is unpopular with House Democrats. Instead, they would declare the Senate bill passed once the House votes to approve the changes.

They want to hide what they're doing from the American people -- who they seem to view as an obstacle, Senate Republican leader Mitch McConnell said.

The bill incorporating the House changes would then be approved by the 100-member Senate under budget reconciliation rules that require only a simple majority, bypassing the need for 60 votes to overcome Republican procedural hurdles.

House Democrats want assurances from the Senate that it will go ahead and approve the changes they are seeking. Senate Democrats were developing a letter that could offer some assurance.

House Speaker Nancy Pelosi said she was confident they would get what they needed. They'll tell us what they think they can do and we'll let them know if that works for us. But I don't see it as a problem, Pelosi said.

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