Three days of oral arguments at the Supreme Court have given Republicans reason for optimism that President Obama’s health-care law could be heading for a legal defeat in a few months. But would such a victory for the GOP this summer mean political success for the party in November and beyond?

No one can say with any certainty what the justices will decide. But the individual mandate — the symbol of all that conservatives loathe about the new health-care law — appears to be in trouble, based on the give and take at the high court. And Justice Antonin Scalia argued that if the mandate is ruled unconstitutional, the entire law should fall with it.

Such a ruling would be a major win for opponents of the federal statute. But it could come with complications. First, a party that has built its health-care message on the phrase “repeal and replace” would immediately come under pressure to reach consensus on how to reform the health-care system. Second, Republicans, who benefited from a sizable enthusiasm gap in the 2010 midterm elections, could face a Democratic opposition deeply angered and newly motivated by its setback in the high court.

Republican pollster Whit Ayres summed up the political consequences of the court overturning Obama’s law in part or in whole: “If the court strikes down just the individual mandate but leaves the rest of an increasingly unstable and unworkable structure, then the GOP has an ‘I told you so’ moment and an even greater argument for repeal. If the court strikes down the whole law, then the GOP has a huge ‘I told you so moment,’ but loses one of several large targets for the fall campaign. There are plenty of other targets remaining (jobs, stimulus, fiscal irresponsibility), but it loses a big one.”

For almost three years, health care has been the energizing force inside the conservative movement. It is arguable that the new legislation, as much as Obama’s stimulus spending, created the tea party movement that helped power Republicans to victory in 2010, and there’s no doubt that it has remained the most powerful organizing message for GOP candidates. The legal battle over the law has helped bind conservatives together in common cause at a time when the Republican presidential nominating contest has been a disappointment to many in the party.

Republicans have been far more united around the concept of repeal than replace, however. Coming together around a replacement for Obama’s comprehensive solution to rising costs and a lack of insurance among about 45 million Americans will be a major challenge. Up to now, Republicans have offered generalities, not a plan.

Many of the provisions of the current law are enormously popular, among them the prohibition against denying coverage for people with preexisting conditions and the ability of young people to stay on their parents’ insurance until age 26. Some ideas that Republicans have long advocated are also popular, among them tighter limits on medical malpractice lawsuits.

Republicans favor market solutions to many of the problems of today’s health-care system. Mitt Romney, who supported an individual mandate for Massachusetts when he was governor, says states should take the lead in reforming health care, a view most shared by most Republican officials. But what uniform standards, if any, should apply to the system, and what role would the federal government have to set those standards under a Republican plan?

Critics of the president’s plan said it did not do enough to control costs. Do Republicans have politically palatable answers to offer if the court decides the law should be scrapped?

Obama often said before he became president that there was no shortage of ideas for solving the health-care problem, just a lack of political will. Republicans, if they are tasked with producing an alternative to Obama’s law, will similarly find plenty of conservative ideas from which to choose. But as Obama learned, achieving political consensus is a far bigger hurdle.

Strategists on all sides are thinking about the consequences of the law being overturned. Dan Schnur, director of the Jesse M. Unruh Institute of Politics at the University of Southern California, said both Obama and Romney, should he become the GOP nominee, could use the issue to their benefit.

“For very different reasons, both Obama and Romney will have significant challenges motivating their respective bases this fall,” he said. “So the court could end up providing both sides with a convenient way to get the party faithful excited. Obama tells liberals that the evil [Chief Justice John] Roberts court robbed the country of health-care reform. Romney promises to appoint conservative justices to protect the Constitution. Neither one of them persuades any swing voters by talking about this, but both can use the issue to fire up their bases.”

Democratic strategist James Carville argued earlier this week that a Supreme Court defeat of the law would be good for Democrats. He told CNN’s Wolf Blitzer, “As a professional Democrat, there’s nothing better to me than overturning this thing 5-4 and then the Republican Party will own the health-care system for the foreseeable future. And I really believe that. That is not spin.”

Some Republicans disagree that victory would be costly for the GOP. Rob Stutzman, a California-based strategist, said, “A November election about picking up the pieces of a struck-down health-care reform law is likely a huge boost for Republicans and only motivates their base, including the tea party.”

Jim Dyke, a South Carolina-based strategist, said that, although a far-reaching victory in the high court would take away the “repeal” battle cry from GOP candidates, it would provide an exclamation point to more than two years of assertions that the president has been a failure in offering solutions to the country’s big problems. “It reinforces [that] Obama is in over his head,” he said.

Bill Palatucci, a Republican National Committee member from New Jersey, disagreed with Carville’s assessment. “A win by those opposing the law will create a burst of positive enthusiasm, which will embolden tea party activists and Republicans to work together in the coming fall election,” he said. “Rather than being angry but dejected, a win at the Supreme Court would bring energy, momentum and new spirit up and down the GOP ticket.”

Republican optimism at this moment, as everyone awaits the court’s decision, is understandable. A ruling that goes against the administration would represent a major defeat for Obama and his party. It would end one battle in the GOP’s long fight against the president, but it would begin another. Are Republicans truly ready for what would come next?

For previous columns by Dan Balz, go to