A year after its passage, more than half of the historic health care law has been implemented but the battle over its future has grown more fierce.
"America will never become the nation it can be if were saddled with 'Obamacare,'" Rep. Steve King, the Iowa Congressman who is leading the charge to repeal the health care law, told ABC News. "I have a deep conviction that this is unconstitutional, that this is unsustainable, and I have a duty. And that doesn't mean I sit back and wait for the Supreme Court to save America from itself. It's my job to step up and lead."
In January, the House passed a bill repealing the health care law in one of its first orders of business.
But the road for critics of the law has been rocky. The Senate is controlled by Democrats who will not vote for repeal. Neither of the two short-term continuing resolutions that have been passed contain the provisions repeal supporters are demanding.
But King and those in his camp are standing firm, saying they will vote against any other continuing resolution that doesn't include a clause to defund health care, even if that means defying their own leadership and resulting in a government shutdown.
"I stood up before conference two weeks ago or so and said I will vote no on any CR that doesn't include language that cuts off the funding to Obamacare. I am done negotiating," King said. "I took that stand and I will hold that stand. I have spent the last year and a half fighting Obamacare and I hope I don't have to spend the next year and a half, but I will."
The public, while still skeptical and confused by the law, is divided over whether it should be repealed. In a March poll by the non-partisan Kaiser Family Foundation, only 21 percent of those surveyed supported repealing the law, while a bigger group, 30 percent, said it should be expanded.
In fact, a majority of Americans, according to the poll, want to keep major elements of the law except the individual mandate clause. One of the backbones of the health care law, the mandate requires that every American, with the exception of a small group, must have health insurance by 2014.
The chances of a full repeal look slim, but there's no question that the law will be subject to changes even as it is being rolled out. House Republicans have the power to defund parts of the law, preventing it from going forward as planned.
Last month, the Senate passed an amendment that would strip the onerous requirement on small businesses to report any business transactions that are greater than $600.
President Obama has already thrown his support behind the State Innovation Waiver, which would waive states from the mandates of the health care law as long as they provide comparative alternatives and costs are the same.
But the battle that is brewing on the state level is another that is posing a significant challenge for the Obama administration.
More Than Dozen States Oppose Health Care Law
When the health care legislation was signed a year ago the conventional wisdom was that it would be upheld by the courts. But critics of the law, emboldened by the filings of conservative state attorneys general as well as the rulings of two federal judges, now argue with more force that the law might be in eventual jeopardy.
More than two dozen states have sued the Obama administration to block the law from being fully implemented.
Three federal judges -- appointed by Democratic presidents -- have upheld the law, and two federal judges -- appointed by Republican presidents -- have struck down its key provision, the individual mandate. One of them, Judge Roger Vinson in Florida, went as far as declaring the whole law unconstitutional and said all of it "must be declared void."
Unlike the cases where the ruling was in favor of the Obama administration, those in Florida and Virginia were brought by states as opposed to private parties. The Florida case, in particular, included 26 states.
The matter is likely to be taken up by the Supreme Court in the coming years although the timing of it remains blurry. Although the cases are wending their way through the appellate courts, Virginia's attorney general is asking the Supreme Court to step in and address the issue immediately.
That request is expected to reach the high court at the beginning of April, and court watchers believe it will be denied. The high court does not usually like to step in prematurely before the appellate courts have ruled.
If there is a split in the appellate courts, as expected, the Supreme Court could review the merits of the case sometime next term with a decision around June of 2012.
This fresh battle outside of the Beltway comes at a time when the states' role in implementing the law is becoming increasingly important.
"As we look forward with implementation of the health reform law, the states really become the focus now," said Jennifer Tolbert, a principal policy analyst at the Kaiser Family Foundation. "When thinking about the coverage expansions in particular because it is going to be up to the states to implement the expansion of the Medicaid program for lower-income individuals and to create the new health insurance exchanges that will provide access to private insurance for moderate and middle income individuals."
Much of the investment, such as for Medicaid expansion, comes from the federal government but states will eventually have to bear the costs.
Several governors, particularly Republicans, are resisting the changes saying they cannot sustain the costs and infrastructure investments in the long-term.
Reducing costs in the long term was one of the key points pushed by Democrats and the president, but health care experts say it's too soon to tell whether the law will make a significant impact in Americans' wallets.
ABC News' Karen Travers contributed to this report.