WASHINGTON-Lawmakers from both parties on Capitol Hill agreed on just two points Friday afternoon: This weekend is crunch time for one of the biggest legislative measures in the history of Congress and the vote will be tight.

The final showdown in the epic yearlong congressional healthcare battle is this Sunday, and it will be a photo finish as Democrats aim to place the federal government in the center of the nation's medical insurance industry.

House Speaker Nancy Pelosi, speaking Friday at the Capitol, and President Barack Obama, speaking at George Mason University in Virginia, both stressed the historic nature of the vote as they tried to claim momentum before Sunday.

"We may not have chosen this time but this time has chosen us," Pelosi said just outside the House chamber where members are expected to cast the climactic vote sometime Sunday afternoon.

But while Democrats flashed smiles to reporters and television cameras throughout the day Friday, the party still lacks the 216 votes needed to pass its $940 billion measure. Although repeatedly pressed by reporters, Pelosi would not claim whether she had the votes, saying instead, "When we bring the bill to the floor we will have a significant victory for the American people."

But House Republican Leader John Boehner, speaking a few minutes later across the Capitol, continued to stress that the American people do not want a bill that cuts $523 billion from Medicare and increases taxes by nearly $650 billion.

"Republicans can't beat this bill, but the American people will," Boehner said. "They are screaming at the top of their lungs just saying stop."

Indeed conservative groups have sent hundreds of people to make personal protests at congressional offices while thousands more are jamming congressional phone banks.

"I'm here because of what's going wrong in Washington, D.C.," said Bill Petrovic, 69, of Rockaway Beach, Mo., during a Tea Party-sponsored protest at the Capitol earlier this week. "It's the shredding of our Constitution."

Petrovic's wife, Beverley, nodded and said, "Our children and grandchildren and one great-grandchild are going to have to pay for this healthcare bill."

But Democrats remain so committed to their healthcare plans that they are still floating a tactic where they could "deem" the controversial Senate bill passed without forcing individual House lawmakers to cast a vote that could cost them reelection this November.

But even reform supporters acknowledge that this would be a tainted victory and leave Democrats open to campaign attacks. The preference remains to hold an actual vote this Sunday.

That is why Obama, who canceled an overseas trip this weekend, will continue to twist arms with a special appearance on Capitol Hill Saturday afternoon. In his meetings with Democrats so far he has stressed that his presidency hinges on passage of the healthcare bill.

Four of the 39 Democrats who voted against healthcare in November have switched their votes. Rep. John Boccieri, D-Ohio, became one of the latest, telling reporters: "I'm not worried about the election. I'm worried about doing what's right."

Other "no" to "yes" switches include retiring Rep. Bart Gordon, D-Tenn., a fiscal conservative, and freshman Rep. Betsy Markey, D-Colo.

The Democrats' 2,309-page healthcare bill creates about 160 boards and regulatory agencies to oversee elements of healthcare. The Congressional Budget Office estimates that 9 million people will lose their current insurance coverage by 2019 under the proposal.

Meanwhile, a hefty $434 billion expansion of Medicaid would place an additional 16 million Americans into the government plan, with families making as much as $88,000 eligible for federal assistance.

By 2014, Americans for the first time would be required to buy insurance or face penalties. The plan imposes a $2,000 fine on businesses that cannot provide their workers with health coverage, and applies those taxes to both part-time and full-time workers.

While a special deal giving extra Medicaid money to Nebraska was removed from the latest bill, other special deals criticized by even Democrats stayed in. Boehner and other Republicans promised to reveal every special deal brokered in exchange for fence-sitting votes in what will surely be a wild weekend.

"We will be hearing about this bill for a long time," promised Boehner.

This week, Democrats also rolled into the bill another one of Obama's domestic priorities: placing federally guaranteed student loans solely in the hands of the government, meaning banks and other for-profit lenders will not be able to participate. As a result, this bill now does not only put the government at the epicenter of healthcare, it also allows the government to take over the student loan program.