WASHINGTON >> House Republicans are not waiting for the Supreme Court verdict on the new health care law to plot their strategic response. If the measure is not thrown out entirely, House leaders plan to force a vote immediately to repeal the law to reinforce their deep opposition to the legislation, opposition that has become central to their political identity.

The emerging game plan for the Republicans who control the House is just one element of the coordinated planning by groups on both sides of the issue as the Supreme Court ruling approaches as early as next week. The Republican National Committee, in consultation with congressional campaign offices and Mitt Romney’s presidential campaign, is readying a war room. The National Republican Congressional Campaign has mounted a petition drive for repeal, complete with a function to allow signers to watch their faxed petitions arrive over the Internet.

At the White House, which has much riding on the case, top officials continue to project confidence that the court will rule in its favor and that the administration will move on from there to put the law into force. But White House allies and advocates of the new law do not necessarily share that view and are gearing up in the event of an unfavorable decision.

Representatives of groups favoring the law from crucial political battlegrounds converged on Washington this week for two days of meetings to coordinate their political response at the behest of Families USA, one of the law’s most stalwart defenders. Democratic aides on Capitol Hill are readying a comeback intended to force Republicans to show their hand on the issue of the uninsured.

House Democrats have been issued a “pocket card” to carry with them, spelling out in big numbers how the law has already helped people: 86 million who have received free preventive care, 105 million who no longer face a lifetime cap on benefits, and as many as 17 million children who can no longer be denied coverage because of pre-existing health conditions.

And the health insurance industry has started a lobbying and social media effort to drive home its contention that popular regulatory provisions in the law cannot survive if the Supreme Court strikes down the mandate that all Americans buy health insurance.

“Our focus is making people understand the inextricable link between the coverage mandate and the rest of the insurance regulations,” said Robert Zirkelbach, a spokesman for America’s Health Insurance Plans, the insurance industry group behind a campaign known simply as “The Link.”

The Supreme Court’s decision is expected as early as next week but more likely the following week. Rarely in the Court’s history has a decision had so much riding on it, for the economy, for the vast health care industry and for the nation’s body politic — from the White House race to the 435 House campaigns.

After a burst of prognostication around oral arguments over the health care law, known as the Affordable Care Act, groups on both sides have fallen back into a state of nervous anticipation. No one is certain how the court will rule, or how the politics will shake out in the aftermath.

Lawmakers, political strategists and activists are preparing for three contingencies: The court upholds the law, the court invalidates the insurance-purchasing mandate but preserves most of the law, or the court throws out the law, President Barack Obama’s signature domestic achievement. In the event that the law it is crippled or eviscerated, the contest will be to ensure that the other party is held responsible, not only for the popular provisions that are lost but what comes next for the 46 million Americans still without health insurance.

Rep. Eric Cantor of Virginia, the House majority leader, said unless the court throws out the law in its entirety, House Republicans intend to push the issue back to the floor of the House and call for its repeal.

Since Republicans believe that health insurance companies are contractually obligated to maintain some of the most popular provisions, like allowing adults under age 26 to remain on their parents’ health plans or ending lifetime payment caps, until the next open insurance enrollment period, they contend there will be less pressure on Republicans to produce the “replace” part of their promise to “repeal and replace” the Affordable Care Act. Republicans say their view was bolstered by recent signs from the health insurance industry that they will retain some popular benefits.

“I don’t think we would take the step of countering with a comprehensive, thousands-of-pages bill like Obamacare, no,” Cantor said. “I don’t think that’s what the country wanted. I think that’s what scared so many people.”

After a repeal vote, Republicans plan to first let the dust settle. Then, Cantor said, they would move forward incrementally with bills to allow the purchase of insurance across state lines, to loosen restrictions on consumers wishing to change insurers, and to bolster tax-preferred health savings accounts.

When several Republican lawmakers suggested popular parts of the health care law would be maintained, conservatives revolted. House Speaker John A. Boehner of Ohio stepped in to say the law must be wiped clean before any next steps are taken.

A senior Republican House aide said it was up to the White House, not Republicans, to produce a contingency plan for those left behind by a court invalidation, like the thousands of sick people or consumers with pre-existing conditions in new federally backed high-risk pools.

Even before those moves, advocates are trying to seed the political battleground. The conservative group American Crossroads and Crossroads GPS began a $4.6 million advertising campaign against six Democratic Senate candidates Wednesday, including an attack on Heidi Heitkamp of North Dakota centered on “Obamacare.”

On the other side of the issue, Ron Pollack, executive director of Families USA, said advocates of the law from the most politically important states are gathering to coordinate messages for the week ahead. The most important task is to impress on voters that the court’s ruling will likely have no impact on the heart of the health care law — health coverage to the uninsured, started in 2014, through the expansion of Medicaid, the establishment of state-run health insurance exchanges and tax subsidies for the purchase of private insurance plans on those exchanges.

The Supreme Court may well toss out the mandate to purchase insurance, and without that mandate, two of the most popular regulations may have to go, the ban on denial of coverage for pre-existing conditions and an end to variable insurance rates for different populations.

“If the court invalidates the mandate and invalidates those two key insurance market reforms, we need to make sure the public does not see that as meaning the law is killed,” Pollack said.

© 2012 The New York Times Company