Armed with detailed legislative language and a report on the bill's costs from the Congressional Budget Office, Democratic leaders and White House officials began a new round of arm-twisting to line up the final votes they will need to pass the legislation when it comes to the House floor Sunday in the face of intense Republican opposition.
Democratic leaders were still struggling Thursday to lock in the 216 votes they need to pass the bill. They are believed to be at least a half-dozen votes short, but said they were confident they could secure the needed votes.
With the fate of his signature initiative still up in the air, President Obama canceled a foreign trip that he had been scheduled to start Sunday to be on hand for the final House vote and a subsequent round of voting that would begin in the Senate next week to complete work on the bill.
The legislation’s chances seemed to be improved by the budget office report, which estimated that it would reduce projected federal budget deficits by $138 billion over the next decade, with additional tax revenue and Medicare savings. Many of the House Democrats who have continued to waver over the bill had been concerned about the bill’s long-term costs. The bill would provide insurance coverage to most of the uninsured, put new restrictions on insurers and seek to lower rising health care costs.
The version of the bill unveiled Thursday is based on the bill passed by the Senate in December, but it incorporates a package of changes that would address concerns raised by House Democrats. Under the timetable outlined by Democratic leaders, the House on Sunday would pass the Senate bill and then immediately approve a package of changes. If signed by Mr. Obama, the first bill would become the law of the land, but the second one would go to the Senate, where it could be approved by a simple majority, using a procedure intended to avoid the threat of Republican filibuster.
Representative Bart Gordon, Democrat of Tennessee, cited the deficit-reduction figure in announcing Thursday that he would switch his vote and support the new bill. Mr. Gordon, a member of the fiscally conservative Blue Dog Coalition, voted against the House bill in November.
Another Blue Dog Democrat who voted no in November, Representative Betsy Markey of Colorado, said she too would support the new measure.
But a few House Democrats, including Representatives Michael Arcuri of New York and Stephen F. Lynch of Massachusetts, said they were moving in the opposite direction.
Mr. Arcuri, who supported the bill in November, said he would vote against the new package because it did not do enough to lower insurance costs.
Mr. Lynch issued a statement saying he was opposed to the Senate bill — and to a plan being considered by Democratic leaders to pass it without explicitly voting for it. The House should take “a straightforward up-or-down vote on a bill of this magnitude,” he said.
The No. 3 Democrat in the House, James E. Clyburn of South Carolina, said, “We are absolutely giddy” over the report from the budget office.
Republicans minimized the significance of the latest cost estimate, deriding the 10-year budget savings as paltry compared with what they called the staggering scale of the government’s debt.
Democrats see no prospect of obtaining any Republican votes for the bill, a top priority for Mr. Obama and Speaker Nancy Pelosi of California.
“Passage of health care reform is of paramount importance, and the president is determined to see this battle through,” Robert Gibbs, the White House press secretary, said in announcing the Mr. Obama had postponed until June his plan to travel to Indonesia and Australia.
Officials said that Senate leaders would spend Friday conferring with the Senate parliamentarian over the specific legislative language to determine if any provisions may be struck out for failing to meet the requirements of the complex process being used to alter the Senate bill, known as budget reconciliation.
Senior House Democratic aides said the decisions by the Senate parliamentarian could result in a final package of amendments, in the hope that the House could approve a bill on Sunday that would not require any further changes in the Senate.
Under the bill, the budget office said, the federal government would spend $940 billion over the next 10 years to provide coverage to 32 million people who would otherwise be uninsured.
The price tag, though higher than $875 billion cost of the Senate bill, is lower than the limit of $950 billion suggested by Mr. Obama.
The cost of the bill results from a significant expansion of Medicaid, to cover 16 million more low-income people, and the payment of federal subsidies to help moderate-income people buy health insurance on their own.
House Democrats said they had reduced the impact of a proposed tax on high-cost employer-sponsored health plans. White House officials have described the tax, included in the Senate bill, as a way to slow the growth of health spending.
Labor unions dislike the tax, but the A.F.L.-C.I.O. endorsed the overall legislation on Thursday.
Richard L. Trumka, the group’s president, said unions would “do everything we can” to lobby Congress on the bill.
Under the Senate bill, the tax on high-cost health plans would have raised $149 billion over 10 years. The new legislation delays and reduces the tax, slashing expected revenues to $32 billion.
Democrats would make up for some of the lost revenue by increasing the Medicare payroll tax and extending it to capital gains, dividends, interest and other “unearned income” of people with adjusted gross incomes over $250,000 for married couples and $200,000 for individuals.
The new Medicare tax would raise $210 billion over 10 years, more than twice as much as the $87 billion generated by the comparable provision of the Senate bill, according to the Congressional Joint Committee on Taxation. Fees and taxes under the new bill would total $438 billion over 10 years, up from $399 billion in the Senate bill.
Representative Luis V. Gutierrez, Democrat of Illinois, said he decided to vote for the health care bill on Thursday after receiving assurances from Mr. Obama that the White House would press forward with an immigration overhaul this year. “I feel that what I have from the White House is a commitment to bring more enthusiasm, to make it a great priority to get immigration reform done this year,” said Mr. Gutierrez, who voted for the House bill in November but was noncommittal in recent days.
Ms. Pelosi said she was ready for a fierce fight. Insurance companies “will do anything to stop this legislation,” she said, asserting, “They have made a fortune off of the misfortune of the American people.”
The Senate Republican leader, Mitch McConnell of Kentucky, said the new legislation was “worse than the Senate bill.” In the first decade, Republicans said, the picture is too rosy because many of the taxes and fees would start immediately, while the major costs would not show up for several years.