WASHINGTON (AP) - The Supreme Court's ruling on the constitutionality of President Barack Obama's health care overhaul is likely to shake the presidential election race in early summer. But the winners in the court will not necessarily be the winners in the political arena.

No doubt, a decision to throw out the entire law would be a defeat for Obama. His judgment and leadership, even his reputation as a former constitutional law professor, would be called into question for pushing through a contentious and partisan health insurance overhaul only to see it declared unconstitutional by the court.

But it would not spell certain doom for his re-election. In fact, it would end the GOP argument that a Republican president must be elected to guarantee repeal of the law. It also could re-energize liberals, shift the spotlight onto insurance companies and reignite a debate about how to best provide health care.

If the court upholds the law, Obama would be vindicated legally. Republican constitutional criticisms would be undercut because five of the nine justices were nominated by Republican presidents.

But opposition would intensify in the political world. Without legal recourse, Republicans would gain new energy to argue that the only path to kill the law would be to elect a Republican president and enough GOP candidates to control the House and Senate. They might be wary of promising overnight repeal because a filibuster-proof Senate majority seems beyond their reach in the November election.

Central to the dispute over the law is a provision that requires individuals to have health insurance by 2014 or pay a penalty. Polls show that this mandate is opposed by 3 of 5 Americans. Among Republicans, calls for its repeal are a surefire applause line.

Of the four federal appeals courts that have ruled, two upheld the law, one struck down only the insurance mandate and one punted, saying an obscure tax law makes it premature to decide the merits until the main coverage provisions take effect in 2014.

With the court hearing arguments Monday through Wednesday, operatives from both parties have been playing out the potential outcomes. It's a calculation complicated by the intensely polarized public attitudes toward the law, by the still unsettled race for the Republican nomination and, most important, by the range of potential decisions by the court.

‘‘A lot of the arguments that are being made against it right now are that they violate basic constitutional rights and principles,'' said Tad Devine, a veteran consultant of Democratic presidential politics. ‘‘If the Supreme Court, controlled by Republicans, doesn't agree with that, I think it's going to be hard to make that argument.''

‘‘If they strike down the mandate,'' he added, ‘‘it takes away a lot of the attack against the president on that issue.''

White House and Obama campaign officials would not publicly discuss the options ahead, worried they would be perceived as trying to influence the court. But the Obama campaign has begun to draw attention to the benefits of the law, hoping to counter the beating the law has taken from the GOP presidential candidates.

This past week, it posted a new health care app online where users can find out how the health care law affects them. It also launched a website that features testimonials about the law.

The campaign's Obama Twitter account drew attention Thursday to that ‘‘Faces of Change'' website and to the law's second anniversary, a day after White House spokesman Jay Carney dismissed any observance of the bill's signing as something ‘‘that only those who toil inside the Beltway focus on.''

On Friday, the White House released a report that promoted achievements such as coverage for young adults and omitted any mention of problems, including the little or no progress toward carrying out the law in many states. Health and Human Services Secretary Kathleen Sebelius said in a statement the law ‘‘gives hard working middle-class families the security they deserve.''

Privately, many Democrats concede that repeal of the law would be represent a huge public relations problem for Obama, though one he could overcome if the court issues its opinion in June, as expected.

Republicans appear divided on the results.

Republican strategist Greg Mueller, who works on many conservative causes, said that if the law is upheld, the conservative base will be energized; if the law is declared unconstitutional, it will display Obama's overreach.

‘‘I don't think there is a bad scenario for Republican candidates,'' he said.

Not all see it that way.

Republican Rep. Steve King of Iowa said this past week an Obama victory would be more assured if the court strikes down the individual mandate, as King would like.

‘‘I think then that there is more risk that President Obama will be re-elected because people will think they are protected from this egregious reach into our freedom,'' King said.

‘‘If the Supreme Court finds it constitutional,'' he added, ‘‘then I believe Barack Obama will not be re-elected because they will understand that they have to vote him out of office to repeal it.''

The public's broad respect for the Supreme Court as an institution is also a factor.

‘‘I think a wide swath of the people will say ‘if the court says it's kosher, then it's kosher.' I think in many ways that will be the final word,'' said John Feehery, a former top Republican House leadership aide. ‘‘That doesn't mean the controversy is going to go away because this law is so massive and has so many parts that haven't been implemented yet, including the individual mandate.''

The court's decision could affect the Republican presidential contest, too.

A court opinion in June would come at the tail end of the GOP primaries and ahead of the Republican National Convention.

Former Sen. Rick Santorum of Pennsylvania has elevated the health care law to his top campaign issue. He argues he would be best equipped to carry the repeal banner. Front-runner, Mitt Romney, as governor of Massachusetts, signed into law a health overhaul similar to Obama's, with an insurance requirement as part of it.

Romney has said he would seek to repeal the federal health care law, but has stood behind Massachusetts'. He argues these decisions should be left to states.

‘‘Well, that's pretty compelling,'' Santorum countered sarcastically Wednesday at a rally near the shores of Louisiana's Lake Pontchartrain.

‘‘Why would conservatives, Republicans, take the biggest issue in this race - freedom, and its impact on the economy, on your life, on your economic well-being, on your religious liberty - why would we take that issue and turn it around and give it to Barack Obama instead of using it like a sledge hammer?'' he asked.

It's a case that Santorum pledges to take all the way to the floor of the convention, if he somehow manages to accomplish his long-shot goal of denying Romney enough delegates to win the nomination outright.