WASHINGTON (CNN) — The heart of the health care law championed by President Barack Obama may be in judicial trouble, but the Supreme Court appeared very inclined Wednesday to keep the rest of the sweeping reform legislation intact.

On the final day of its marathon public debate over the 2010 Affordable Care Act, the justices tackled what would happen if they ruled against the constitutionality of the individual mandate, the key funding mechanism of the law.

At issue Wednesday morning was whether the entire law’s 450 or so provisions would have to be scrapped if the individual mandate were found unconstitutional.

A separate session is scheduled for Wednesday afternoon on whether states would be “coerced” by the federal government to expand their share of Medicaid costs and administration by the risk of losing that funding if they refuse.

Even though the health care law’s “individual mandate”— requiring most Americans to have health insurance beginning in 2014 or face a financial penalty — appeared to be on shaky legal ground, few on the court seemed eager to take the drastic step and invalidate the rest of the landmark legislation.

“There are so many things in the act,” said Justice Ruth Bader Ginsburg, including many provisions not directly related to market reforms such as Native American health care. “Why make Congress redo that? Who should we stop and start from scratch?”

Added Justice Elena Kagan. “Half a loaf is better than no loaf,” meaning some provisions would survive.

And the court appeared in no mood to pick and choose.

“You want us to go through 2,700 pages” of the law, asked Justice Antonin Scalia. “Is this not totally unrealistic … to go through one by one and decide each one?”

Justice Anthony Kennedy said he was reluctant to take on this “awesome exercise of judicial power,” at the expense of congressional discretion.

This week’s hearings are among the most politically charged and closely watched in years, with dueling protests and news conferences outside the court building every day on what is likely to be a central issue of the November presidential election.

With the legal survival of the individual mandate in constitutional jeopardy, the question of “severability” — whether the rest of the law can stand if one part is invalidated — has become more important.

All of this may be moot. If the court decides the mandate is constitutional — even in a narrowly tailored way — they will not even bother to take up the severability question presented Wednesday.

In the morning arguments, the clearly divided court expressed concern over whether Congress would have passed the broad reform package without the key funding mechanism — the mandate — firmly in place. However, several of the justices seemed ready to let lawmakers eventually sort out the specific funding questions with or without the mandate.

After the end of six hours of arguments spread over three days, the nine-member bench will retreat from the public spotlight and get to the real task before them.

They will likely gather as a group in a closed-door conference over the next few days and actually decide on the four health care appeals. Going one-by-one in order of seniority, they will all be thinking of the number five — which is how many votes it will take to achieve a majority.

Once the tallies are sorted out, opinions will be assigned to individuals to craft over the next three months. What the court says in these written opinions — how it interprets the Constitution — will be far more important than what they said in the oral arguments this week.

The rulings may be in essence how legislators, individual Americans and history will judge these justices.

Wednesday’s cases gave the administration another chance to regain the rhetorical offensive and defend the entire law’s validity. Many legal observers concluded the Obama administration’s solicitor general, Donald Verrilli Jr., did little to boost the individual mandate’s constitutionality in two hours of intense arguments Tuesday.

The questioning of Verrilli’s performance was so widespread that the White House issued a statement Wednesday defending him.

“Mr. Verrilli is an extraordinarily talented advocate who possesses a sharp mind, keen judgment, and unquestionable integrity,” said the statement by White House Counsel Kathryn Ruemmler. “He ably and skillfully represented the United States before the Supreme Court yesterday, and we have every confidence that he will continue to do so.”

Wednesday’s first argument dealt with severability, but most court watchers think of it as the “domino effect” issue — if the individual mandate section is ruled unconstitutional, must the entire law collapse as well?

A federal judge in Florida had so ruled in February 2011, saying: “Because the individual mandate is unconstitutional and not severable, the entire act must be declared void.”

However, a federal appeals court subsequently overruled on the severability question while upholding the individual mandate’s unconstitutionality.

Opponents of the law say the individual mandate is crucial to its overall impact, since it is the main funding mechanism for the expansion of a range of other programs. This might be the one question on which the justices will ultimately agree in favor of the government.

Then comes the Medicaid “coercion” question, which can be seen as the” national policy implications” issue.

Separate lawsuits by 28 Republican-led states say the new law’s significant expansion of the social safety net unconstitutionally “coerces” state governments.

Medicaid is administered by the states with a combination of federal and state money. It currently required coverage only for poor children and their parents or caretakers, adults with disabilities and poor individuals 65 or older. The “coercion” issue was surprisingly added to the health care debate by the Supreme Court justices.

Both sides of the issue agree that what the high court decides on Medicaid could have broad implications for the regulatory ability of the federal government to set long-term national policy goals in areas such as the environment, education and the workplace.

Some states have long complained their autonomy is being eroded by creeping federal intervention on spending matters.

Article 1 of the Constitution gives Congress the power to “lay and collect … taxes to pay the debts and provide for the common defense and general welfare of the United States” and to “regulate commerce … among the several states.”

Such authority has long been broadly interpreted, including when imposing conditions on recipients, be they individuals or states. No federal court has ever ruled states have been unlawfully coerced when they accept conditions or strings attached to federal funds. The Supreme Court in 1987 affirmed that congressional discretion.

Starting in 2014, the health care law’s Medicaid changes would make millions of additional Americans eligible for benefits by raising the income cap for qualification. That would include all adults up to 133% of the federal poverty line.

The tricky point is that states are not forced to agree to the law’s incremental Medicaid increases, spread out over six years. The states could instead abandon their participation in the program, but they say that would be a financial, social and political catastrophe — one which they cannot realistically accept.

Supporters of the health care law say the Medicaid issue involves political motivations rather than real policy concerns.

“These arguments aren’t based on Medicaid’s health outcomes among children or seniors,” Dr. L. Toni Lewis, the health care chair of the Service Employers International Union, said at a news conference Wednesday. “They aren’t based on testimony from those who have received services from Medicaid. They aren’t even based on data that shows how well Medicaid controls costs compared to private insurance. That’s because the challenge to Medicaid in the Supreme Court isn’t based on what’s good for our health. It’s just based on politics and posturing.”

Through this issue, the long-standing fight over “federalism” and the leverage the national government wields over states might soon reach epic levels with a high court decision either strengthening or limiting congressional authority on this and potentially a host of other regulatory areas.

The cases argued Wednesday were National Federation of Business v. Sebelius (11-393) and Florida v. Department of Health and Human Services (11-400).

— CNN’s Tom Cohen contributed to this report.