Three days of oral argument before the Supreme Court last week left the future of the national's health care act more murky than ever, at least in the eyes of outside observers.

Many legal experts, such as lawyer Jeffrey Toobin, a legal analyst who writes for The New Yorker, walked out of the court with the impression that the Affordable Care Act is in serious danger of being partially or wholly overturned.

"This law looks like it's going to be struck down," Toobin said on CNN after the second day of hearings. "I'm telling you, all of the predictions, including mine, that the justices would not have a problem with this law were wrong. I think this law is in grave, grave trouble."

Others weren't so sure, noting that it can be risky reading too much into what the justices said in open court.

"Before the arguments started, if you asked me my prediction, I would have told you that I thought it would be a very close case and I would put my money on the court upholding the law by a 5-4 decision -- and that's still what I would say," Gregory Magarian, a professor at Washington University School of Law in St. Louis, told HealthDay.

Even so, Magarian said that "it's hard to look at it and say it's a slam-dunk that they're going to uphold the thing."

Officials with the American College of Physicians believe it's too soon to hit the panic switch, given how difficult it can be to tell what the Supreme Court justices are thinking or how they will ultimately rule.

"Experts will tell you that you can't predict based on oral arguments which way the court will go," said Bob Doherty, ACP's senior vice president for governmental affairs and public policy. "I think we need to wait and see. People who try to draw definitive conclusions based on oral arguments often are wrong."

The Supreme Court is expected to issue its ruling in June.

In the meantime, ACP is focusing on what the health care law has already accomplished and what could happen if it were dissolved in whole or in part.

In a statement released before the oral arguments, Dr. Virginia Hood, ACP president and a professor of medicine at the University of Vermont, said the law "has resulted in major improvements in access and coverage for tens of millions of Americans seen by internal medicine physicians."

"Considering that it is just a little over two years since the ACA was enacted into law, and many of its programs are not yet fully effective, the ACA has had notable success in improving health insurance coverage," Hood said. "Looking to the future, the ACA will ensure that nearly all legal residents in the United States will have access to affordable coverage beginning in 2014 if the law is allowed to be fully implemented."

People who already have benefited from the Affordable Care Act's provisions, Hood said, include:

• 2.5 million young adults, 19 to 25 years old, who have been allowed to stay on their parents' health insurance plans
• 1.28 million Americans covered by Medicare who got discounts on brand name drugs in the Medicare Part D coverage gap through the end of July 2011, saving them an estimated $660 million
• More than 18.9 million Medicare beneficiaries -- about 55 percent of the program's participants -- who have received one or more preventive services at no out-of-pocket cost to them
• About 10.5 million people in low-income or rural areas who have been treated by doctors with the National Health Service Corps, which receives mandatory funding under the ACA and has awarded nearly $900 million in scholarships and loan repayment funds to health care professionals.

Coming reforms will, by 2014, prevent insurance companies from denying coverage to people with pre-existing conditions and expand Medicaid to cover everyone with income up to 133 percent of the poverty level.

"When these and other programs enacted by the ACA become fully implemented by 2014, it is estimated that 94 percent of legal residents in the United States will have access to affordable health insurance coverage, with 32 million persons who now have no health insurance being able to obtain coverage," Hood said. "This will be an historic achievement in improving the health of the American people."

On the other hand, America's health care system could face hard times if the court overturns specific parts of the Affordable Care Act or chooses to strike down the law altogether.

A ruling that would eliminate the so-called "individual mandate," for example, could make untenable the parts of the law that require coverage for everyone, including the sickest.

"Without an individual insurance requirement, some people may wait to obtain insurance until they are sick, aware that insurers will not turn them down or charge them higher premiums," Hood said. "This will drive up premiums for everyone else, causing more persons to drop coverage, and potentially resulting in millions more uninsured persons."

Doherty said that he believes a ruling that would find the ACA's Medicaid expansion unconstitutional would have far larger ramifications.

Medicaid operates as a federal/state partnership. The Affordable Care Act requires states to expand their Medicaid coverage so that the partnership can continue, something that the states argue is unconstitutionally coercive.

A ruling that sides with the states "could undermine the structure of Medicaid going forward," Doherty said, because federal authority to use its funding power to promote state-level policy would come into question.

It doesn't stop there, either, he said, because for decades the federal government has used the power of the purse to guide the states. For instance, most states have a minimum drinking age of 21 because that has been linked to eligibility for federal highway grant funding.

"It could lead to legal challenges in a lot of other federal programs that involve a quid pro quo," Doherty said.

However, the darkest possibility, he indicated, would involve a complete and total rejection of the Affordable Care Act by the Supreme Court.

"That's going to create absolute chaos in the country," Doherty said. Physicians wouldn't know whether to continue providing preventive services for free to Medicare patients. Insurance companies could choose to kick young adults off their parents' health plans. Medical students who were planning on National Health Service Corps scholarships or loan forgiveness -- funded through the ACA -- may find that there no longer will be any money available and some might drop out of school. And some rural areas could lose NHSC-funded doctors."

"It's like throwing a hand grenade and expecting the results to be orderly, to produce something that can be put back together again," Doherty said. "It won't happen that way. Federal regulatory agencies will have to work overtime to decide how things will operate."

Because of this, Hood said, the ACP "fervently hopes that the Supreme Court will chart a course that does not derail implementation of the ACA's key programs to expand coverage, while responsibly carrying out the court's constitutional obligation to clarify the constitutional questions."

"And we hope that a day will come when Congress will be able to move beyond a partisan debate over 'repeal and replace' of the ACA to discussion of bipartisan improvements that could be made in the law, without sacrificing the commitment it made to helping nearly all Americans obtain affordable health insurance coverage," she concluded.