Washington, D.C ? President Barack Obama and Democratic leaders lobbied intensively for historic health care legislation today, striving to resolve a last-minute dispute over Medicare while gaining another precious “yes” 48 hours ahead of a climactic vote.

With a showdown set for Sunday on the House floor, Democratic leaders still didn’t command the 216 votes they needed, so every undecided lawmaker was the focus of personal attention from House Speaker Nancy Pelosi and the White House, and every “no”-to-“yes” conversion was trumpeted by party leaders.

Obama, who delayed an overseas trip to help ensure passage of the legislation, planned to meet with Democratic lawmakers at the White House Saturday afternoon.

In an 11th-hour pitch, the president spoke to an enthusiastic crowd at George Mason University in Virginia, lobbing attacks at the insurance industry with his coat jacket off and sleeves rolled up.

“The only question left is this: Are we going to let the special interests win once again, or are we going to make this vote a victory for the American people?” he said.

Obama described the stakes in stark terms, using words uttered so rarely out of the White House that they seem all but banned: “If this vote fails.” What then? “The insurance industry will continue to run amok,” the president said, pointing to rising rates, denials of coverage and limits on care.

Every vote counts

Meanwhile on Capitol Hill, the vote-counting spotlight swung to Rep. John Boccieri, D-Ohio, who announced that he would support the bill despite voting against an earlier version. “I’m not worried about the election,” he said. “I’m worried about doing what’s right.”

Boccieri became the fourth House Democrat to switch from “no” to “yes.” Shortly after he announced his decision, Pelosi predicted: “When we bring the bill to the floor, we will have a significant victory for the American people.”

The good news aside, the White House and Democratic leaders faced a last-minute snag as some lawmakers complained about a provision in the bill on how health providers are paid under Medicare. Pelosi and senior White House officials raced to find a solution.

“I’m a ‘no’ unless they fix it,” said Rep. Peter DeFazio, D-Ore. “We spent months working this out. If we don’t get it in this bill, we will never get it.”

The conversation was all about how Democrats would vote because Republicans have formed a virtually impenetrable phalanx of opposition for the past several months.

Retiring Rep. Bart Gordon, D-Tenn., and first-term Rep. Betsy Markey, D-Colo., announced their support Thursday; liberal Rep. Dennis Kucinich, D-Ohio, did so earlier this week.

The momentum wasn’t all in the right direction for Democratic leaders. Some rank-and-file Democrats who backed sweeping health care legislation when it passed the House in November showed signs of defecting. Weaker restrictions on federal funding of abortion was a concern, but not the only one.

Rep. Stephen Lynch, D-Mass., a former union activist, said even a one-on-one meeting with Obama on Thursday hadn’t convinced him that the legislation did enough to reform the health system and rein in insurers and drug companies.

“I’m still currently opposed,” Lynch said today. “But the president asked me to think about it, and if there were some type of measure that might move me to a better place on the bill, then he wanted to hear about it.”

What’s in the bill

With the addition of the 153 pages of revisions, the bill would expand health care to 32 million uninsured, bar the insurance industry from denying coverage on the basis of pre-existing medical conditions and trim federal deficits by an estimated $138 billion over the next decade.

Beginning in 2014, most Americans would be required for the first time to purchase insurance or face penalties if they refused. Large businesses would face fines if they did not offer good-quality coverage to their workers. Millions of families with incomes up to $88,000 a year would receive government help to defray their costs.

To address concerns of House Democrats, those subsidies were raised by an estimated $25 billion over a decade in the package of changes offered Thursday. Seniors who experience a gap in coverage in the Medicare prescription drug program would receive a $250 rebate this year — an election-year bragging point for Democrats as they look toward the fall campaign with control of Congress at stake. A special deal giving extra Medicaid money to Nebraska was struck in exchange for more Medicaid money for all states, though other special deals decried by Obama stayed in the bill.

The changes also included another of Obama’s top priorities: Federally guaranteed student loans would now be made only by the government, ending a role for banks and other for-profit lenders who charge fees. The savings, an estimated $60 billion over a decade, would increase Pell grants for needy college students as well as support for programs such as aid to historically black colleges, a priority of the Congressional Black Caucus.