After more than a year of negotiations, debate and political drama, President Obama today signed the historic health care bill that could reshape care for millions of Americans while setting up a divisive battle with Republicans that's expected to spill into the November elections and beyond.
"After a century of striving, after a year of debate, after a historic vote, health care reform is no longer an unmet promise," Obama said at an event after the signing ceremony at the Department of Interior. "It is the law of the land."
The president took a direct stab at critics of health care overhaul, saying they are "still making a lot of noise" about what the new law means.
"I heard one of the Republican leaders say this was going to be Armageddon. Well, two months from now, six months from now, you can check it out. We'll look around and we'll see," Obama said to applause.
The president signed the health care bill into law at the White House this morning. He was joined by Americans whose stories have touched the president, and Democrats who voted for the health care bill.
"Today, after almost a century of trying, today, after over a year of debate, today, after all the votes have been tallied, health insurance reform becomes law in the United States of America," Obama said to a standing ovation.
"It's easy to succumb to the sense of cynicism about what's possible in this country. But today, we are affirming that essential truth, a truth every generation is called to rediscover for itself: That we are not a nation that scales back its aspirations. We are not a nation that falls prey to doubt or mistrust," the president added. "We are a nation that faces its challenges and accepts its responsibilities."
The attendees chanted "Fired up, ready to go" -- Obama's campaign slogan -- as the president and Vice President Joe Biden arrived at the East Room.
"Ladies and gentleman, to state the obvious, this is a historic day," Biden said to a cheering crowd before the president took the podium.
As Biden finished his remarks and shook Obama's hand, he was heard on the microphone whispering, "This is a big f-ing deal."
White House Press Secretary Robert Gibbs tweeted soon afterward, "And yes Mr. Vice President, you're right..."
The president said he was signing the bill on behalf of his mother and those Americans, who like her, had to fight with health insurance companies. Obama also hailed lawmakers for making the tough decision to support the health care bill, and taking "their lumps during this difficult debate," in response to which Congressman Gary Ackerman, D-N.Y., shouted, "Yes, we did."
House Speaker Nancy Pelosi, who is credited with bringing together enough Democrats to overcome the final hurdle of passing the bill in the House, received special recognition. As Obama recognized Pelosi as "one of the best speakers the House of Representatives have ever had," the crowd unanimously chanted, "Nancy, Nancy, Nancy."
Vicki Reggie Kennedy, wife of the late Sen. Ted Kennedy, was also present at the event. In an interview with ABC News' Jonathan Karl, Kennedy said her husband would've been "exhilarated" and "thrilled" by the passage of the bill. Sen. Kennedy, who was behind many landmark health bills, made health care reform the mission of his long Senate career.
Before the signing ceremony today, Vicki Kennedy gave Obama a plastic blue bracelet that said "TedStrong." The president and several lawmakers were seen wearing the bracelet. The late senator's son, Rep. Patrick Kennedy, D-R.I., gave the president a copy of the first universal health care bill that his father introduced in the Senate.
But even while there was jubilation at the White House, Republicans promised a tough fight ahead. The Republican National Committee's "Fire Nancy Pelosi" Web site surpassed $1 million in funds raised since the health care legislation passed Sunday evening. Former Alaska Gov. Sarah Palin unveiled a list of 17 Democratic members of Congress who she wants to target in the upcoming mid-term elections.
"We're going to reclaim the power of the people from those who disregarded the will of the people. We're going to fire them and send them back to the private sector, which has been shrinking thanks to their destructive government-growing policies," Palin wrote in an e-mail to supporters seeking to raise money.
On radio and television, conservative commentators lashed out at the lawmakers who passed the legislation.
On his radio program, Rush Limbaugh said, "We need to defeat these bastards. We need to wipe them out."
Glen Beck said, "This bill is still jammed down the throats of America, just enough spiny, dirty weasels went along with it."
Congresswoman Gabrielle Giffords, who voted 'yes' on the legislation, became a target. Her office in Arizona was vandalized over night.
In Florida, Bill McCollum became the first of 14 state attorney generals to file a lawsuit against the health care law. The states' attorney general are filing suits to block the health care law on the grounds that its requirement that everyone have health insurance is unconstitutional.
The lawsuit is "about forcing people to buy health insurance when there's no provision in the Constitution that allows for anybody to be forced to do something when there's no commerce, no action, you're just sitting there," said McCollum. "And it's about the question of forcing the state of Florida and other states against the sovereignty that's guaranteed in the Constitution to our states to do things that are practically impossible to do."
Four state legislatures have already passed laws blocking the bill. On Wednesday, Virginia's GOP Gov. Bob McDonnell will sign the bill into the state's law, making it illegal for the federal government to require Americans to purchase health insurance.
Proponents of the legislation say the health care bill will impact all Americans positively, even those who currently have health insurance.
"I think every American is going to have a more secure relationship with their insurance companies as a result of this because there are a series of protections that will be implemented over time that are important to people," White House senior adviser David Axelrod said on "Good Morning America" today.
Even though the health care bill became law today, the White House's work on it is far from over. The next phase is to sell the changes to the American people, many of whom are still in the dark about what the bill means for them.
The Senate still has to pass the package of "fixes" that were made by Obama and the House of Representatives. The Senate Democratic leadership assured House members that they had the 51 votes needed to pass the reconciliation bill, but they are also gearing up for a spate of procedural face-offs with Republicans. Sen. Jim DeMint, R-S.C., and Rep. Steve King, R-Iowa, introduced bills Monday to repeal the health care bill, and GOP lawmakers are vowing to fight the bill tooth and nail.
Later this week, the president will return to the stump in Iowa to explain to the public how changes in the health care system will affect them.
The White House picked Iowa City because in 2007, then-Sen. Obama delivered his first major speech on health care reform as a presidential candidate at the University of Iowa.
The Congressional Budget Office predicted the bill would cost $938 billion -- mainly through a mix of tax increases and reduction in Medicare spending -- and would reduce the federal deficit by $143 billion in the first 10 years. The health care bill would extend insurance to 32 million more Americans.
Some components of the health care bill will take effect right away, including helping older Americans pay for prescription drugs and preventing insurance companies from denying coverage to children based on pre-existing conditions. There will also be tax credits for small businesses to help them cover insurance costs for their employees. Others, such as the individual mandate and more stringent regulations on insurance companies barring them from placing lifetime caps on coverage, or denying adults based on pre-existing conditions, won't take effect until 2014.
Americans' views on health care overhaul are mixed, depending largely on which poll one is looking at. In a CNN/Opinion Research poll released Monday, 58 percent of those polled said they disapprove of the way Obama handled the health care policy. A CBS News poll also released Monday found that 57 percent of Americans thought Democrats were trying to pass the health care bill because of political reasons, and 61 percent said Republicans were trying to stop it for that same reason.
A poll released by the Kaiser Family Foundation Friday and conducted in March, showed a more mixed opinion amond Americans. It found that 46 percent supported the legislation while 42 percent opposed it.
The health care bill did not get one single Republican vote in either the House or the Senate. Even though the bill is now law, Republicans are still fighting back with promises of lawsuits.
Minnesota Republican Gov. Tim Pawlenty charged on "GMA" today that the individual mandate is an "unprecedented overreach by the federal government forcing individual citizens to buy a good or a service for no other reason than they happen to be alive or a person."
Pawlenty said he sent a letter to Minnesota's Democratic attorney general arguing against the constitutionality of the mandate.
"They've taken it to this big, federalized, bureaucratic, government-run, kind of nanny nation approach," Pawlenty said. "I don't think defending the Constitution and individual's rights under the Constitution, and the relationship between states and the federal government under the Constitution is a frivolous matter."
Axelrod dismissed the lawsuits, saying the Obama administration is very confident the health care bill "will withstand those legal challenges.
"First of all, every single major piece of legislation that's ever been passed in this country has engendered lawsuits. That's the nature of our system, and we expected that," Axelrod said on "GMA." "We're not concerned about these lawsuits."
House Minority Leader John Boehner today assailed the lack of bipartisanship on the bill.
"By signing this bill, President Obama is abandoning our founding principle that government governs best when it governs closest to the people," said Boehner, R-Ohio. "Never before has such a monumental change to our government been carried out without the support of both parties. This debate has fostered unprecedented division at a time when this nation needs to come together and address the serious challenges we face."
Under the health care bill, by 2014 most Americans would be required to have health insurance or pay a fine, with the exception of low-income Americans. Employers would also be required to provide coverage to their workers, or pay a fine of $2,000 per worker. Companies with fewer than 50 employees, however, are exempt from this rule.
ABC News' Z. Byron Wolf and Jonathan Karl contributed to this report.