Though no one outside the Supreme Court has an inkling how it is going to rule on President Obama’s health-care law, the political fallout — at least initially — is easy to predict.

If the law is upheld in full, the decision will be hailed as a triumph for Obama and his leadership. If it is struck down entirely, Republicans will claim vindication in their unanimous opposition to what they see as a massive overreach of government.

And if only part of the law survives, both sides will scramble to reposition. The Obama administration and its allies will do their best to protect what is left. Republicans have vowed to repeal it all as soon as they can, and eventually, to offer an alternative.

However the court comes down, most Americans are not likely to be happy with the result. In a poll released Monday, the Pew Research Center asked about all three scenarios and found that fewer than half of those surveyed would be satisfied with any of them.

The one that garnered the most support — at 44 percent — was throwing out the entire law. Upholding the entire law got the least, at 39 percent. And 40 percent said they would be in favor of striking only the most controversial aspect, which is a mandate requiring individuals who do not receive coverage from their employers or the government to buy it from private insurance companies, or pay a fine.

The Pew survey also found that public preferences tracked sharply along party lines, with Republicans hoping the court will throw out the law and Democrats wanting it to stand.

Partisanship is also certain to drive the initial reaction to the decision, which will land right in the middle of an intensely competitive presidential race.

“It will be heavily politicized, regardless of whatever decision the court makes. It will be overstated, exaggerated,” said former Senate Democratic leader Tom Daschle, who was Obama’s initial choice for health and human services secretary.

In the longer run, however, each of those scenarios raises a whole new set of political and policy questions for the two parties. That means the real implications of the decision are not likely to become apparent until next year.

“No one is going to be in a mood for any fixes, certainly before the election,” said Jonathan Gruber, a Massachusetts Institute of Technology economist who advised the Obama administration in formulating the Affordable Care Act. Gruber also consulted with then-Gov. Mitt Romney, when he was putting together the 2006 Massachusetts health-care law that has many of the same characteristics.

Once the election is behind them, both parties will have to come to grips with either making sure what’s left of the law is working, or deciding whether there is a better way to address the problems of a health-care system that leaves 16 percent of the population without coverage and is gobbling nearly 18 percent of the gross national product.

“It will take a while for people to take a deep breath and say, ‘Okay, now what?’ ” said Gail Wilensky, a critic of the law who was a top health-care policymaker in both Bush administrations. “Then we get back to the serious fight: Is this reflective of the direction we want the economy to go? Is this reflective of the direction we want the government to go?”

Each potential scenario, however, presents a different set of issues and choices down the line:

If only part of the law is struck down

This is, in many ways, the most complicated scenario: The court upholds all of the law except a mandate requiring individuals who do not receive coverage from their employers or the government to buy it from private insurance companies, or pay a fine.

“If the court throws out the mandate and leaves the rest of the law in place, the big question is going to be, does Congress try to go forward with the rest of the law without the mandate?” said former Mississippi governor Haley Barbour, a Republican whose state joined the legal challenge to the law’s constitutionality.

The Obama Justice Department argued before the Supreme Court that if the individual mandate is struck down, other parts of the law should be as well. Those include a requirement that insurance companies cover those with preexisting conditions and a ban on practices that allow health insurers to vary their premiums based on age, gender, health status or other factors.

But forcing insurers and hospitals to cover and treat sick people, without guaranteeing them a pool of less expensive health people to cover the cost, would drive up their prices.

“It does make insurance more expensive, and encourage adverse selection,” in which people wait until they are sick to find coverage, Wilensky said.

And if the costs of insurance soars, even fewer people will buy it — setting off what the insurance industry calls a “death spiral.”

America’s Health Insurance Plans, the insurance industry’s lobbying group, has commissioned studies to show what happened during the 1990s in two states where insurers were required to provide coverage but people were not required to buy it.

In Kentucky, dozens of insurers fled the state, leaving only a handful doing business there; premiums in some cases more than doubled.

In Washington state, the number of people uninsured actually rose by nearly 30 percent, because fewer could afford it from the two insurers who were left in 1999.

Healthcare experts say these experiences suggest what could happen nationally.

But forcing insurers to cover those with preexisting conditions and forbidding discrimination by age and gender are two of the most popular elements of the federal law. That means that politicians may well be under intense political pressure to restore them.

Some states, following Massachusetts’s lead, might themselves impose individual mandates.

Other options include charging a penalty to people who are eligible for coverage but who wait. Medicare has such a system for those who turn 65 but do not immediately avail themselves of its voluntary portions, covering doctor visits and prescription drugs.

If the law is struck down

More optimistic Democrats say this could actually energize their base.

“Right now, the greatest intensity is on the side of people who don’t like the Affordable Care Act,” said William A. Galston, a senior fellow at the Brookings Institution and a former top policy adviser to President Bill Clinton. “But my experience is that a bitter loss mobilizes people.”

That, however, appears to be a minority view among party strategists.

“I just honestly believe that if there is a mobilization, it will be where it has been from the beginning, which is from the right,” said Democratic pollster Peter Hart.

Still, some of the bill’s opponents warn that their side should be careful what it wishes for.

“Initially, it will be an I-told-you-so from Republicans to Democrats,” Wilensky said. “Then the question will be, there’s a problem, so what are you going to do about it? It’s not clear to me how this plays out politically when people step back. ... In some ways, I could argue that [striking down the bill] takes away one of the biggest rallying cries that conservatives have had.”

Republicans say they will have an alternative, though not any time soon.

“We are certainly not going to make the same mistake that Washington Democrats did by rushing through a 2,700-page bill that no one has read,” said Michael Steel, a spokesman for House Speaker John Boehner (R-Ohio).

Steel also suggested that what Republicans envision is an incremental approach — or, as he put it, “step-by-step common-sense reforms that will actually lower costs.”

In the meantime, Boehner cautioned House Republicans in a memo Thursday: “If the Court strikes down all or part of the president’s health care law, there will be no spiking of the ball.  . . .We will not celebrate.’’

If Mitt Romney is elected, the all-but-official Republican nominee has said he would give states the primary responsibility for covering the uninsured. He has also pledged to expand tax breaks to small businesses that cover their workers, allow insurance companies to sell policies across state lines and ensure that people with coverage do not lose it when they get sick.

In the meantime, there is the question of what will happen to some of the provisions of the law that have already kicked in.

Several big insurers last week announced that, regardless of how the court rules, they will keep several of the law’s provisions. Among them are allowing dependents up to age 26 to stay on their parents’ insurance policies, and full coverage of preventive care, such as immunizations and screening.

Unclear, however, is what would happen to those who are already benefiting from other parts of the law. They include the estimated 60,000 people with preexisting conditions who are getting coverage through new federally backed high-risk pools, and seniors who have already saved what the administration says is $3.5 billion from a provision that closes an infamous gap in their medicare prescription drug coverage known as the “doughnut hole.”

If the law is upheld

“If the whole bill is upheld, the president would get a huge boost,” said Robert Blendon, a senior associate dean at the Harvard School of Public Health, who studies public attitudes on health care. “This has taken on a symbolism, not just on health policy, but on leadership and the role of government.”

But the implementation of the law has not yet been fully put to the test.

States will be crucial to making it all work. But as they have waited for the constitutionality of the law to be decided in the courts, many have lagged in setting up the insurance marketplaces — known as “exchanges” — that are called for in the law.

According to a survey by Kaiser Health News, only 15 states have thus far established exchanges. More than 30 states are either studying their options or have not yet acted. And two — Arkansas and Louisiana — have refused to create them.

Many experts and policymakers are doubtful that states will be able to meet their deadline to have the exchanges up and operating.

“Will all of the exchanges really be up and running by January of 2014?” Daschle asked. “I’m dubious.”

As a result, he said, Congress might have to step in and extend the deadline.

But the longer it takes to implement the law, the longer it will take for Americans to realize any benefits they receive from it — which means it is likely to remain unpopular. And Republicans will continue, even redouble, their efforts to get it repealed.

“Any groundbreaking legislation is going to have opposition before the public understands what it means, and how it can help them,” said Democratic pollster Hart. “Without having it in practice, people can more easily understand the downsides than the advantages.”