The battle over President Obama’s health-care law, settled as a legal matter by the Supreme Court, reopened in the political arena Friday as Republicans sought to rebound by refocusing the debate on Obama’s stewardship of the economy.

Stung by the court’s decision to uphold the law, the GOP zeroed in on the portion of the ruling that justified the constitutionality of the individual mandate by casting it as a tax, within Congress’s authority. Republicans argue that the measure represents a massive tax hike on the middle class that will stunt job growth.

“The court has declared that President Obama can have the federal government use its powers of taxation to compel behavior, and that’s one of the most frightening legal aspects of this decision,” Louisiana Gov. Bobby Jindal said in a conference call with reporters that was arranged by the Republican National Committee. “It really raises the question, what’s next? Taxes on people that refuse to eat tofu or refuse to drive a Chevy Volt?”

The attacks drew a sharp response from the White House. In a memo to Capitol Hill Democrats, titled “Winning the Middle Class Tax Battle,” Obama’s senior adviser, David Plouffe, insisted that the health-care law will lower costs for millions of families. He cited projections estimating that less than 1 percent of the population would forgo health insurance and may be subject to federal penalties.

“Republicans in Washington are trying to deliberately misrepresent the President’s record of cutting taxes for the middle class,” Plouffe wrote. “We welcome this debate … and we urge you to seize this opportunity to go on offense.”

The back-and-forth suggested that health care will continue to resonate into the fall, with both sides rallying their troops with extensive fundraising appeals and new television advertisements.

Mitt Romney’s presidential campaign reported that it raised more than $4 million in the 24 hours after the ruling, which has mobilized grass-roots conservative activists who had been cool to Romney in the GOP primary. And American Crossroads, a conservative super PAC, announced that it will launch a national ad campaign on cable television hitting Obama on the health-care ruling.

“Now it’s official: Obama increased taxes on struggling families. The middle class takes another hit,” the ad says.

The Republican Party is betting that November 2012 will be a redux of November 2010, when a backlash against the health-care law helped sweep a wave of tea party Republicans into the House, delivering the speakership to Rep. John Boehner of Ohio.

“I think the Supreme Court’s ruling may have awakened a sleeping giant,” said Ron Christie, a Republican strategist. “Obama may have won the battle in the Supreme Court, but the war is yet to be waged for November.”

Obama campaign spokesman Ben LaBolt said the president’s re-election team also enjoyed a surge in fundraising after the health-care ruling, although he declined to be specific.

In a fundraising email Friday, senior campaign adviser David Axelrod recalled his daughter Lauren’s near-fatal battle with epilepsy that began 30 years ago and, he said, nearly bankrupted his family because of their “lousy” health insurance.

“I was moved to tears when the Supreme Court affirmed the Affordable Care Act, because I know that other families won’t have to face the terror and heartache we knew,” Axelrod said.

The debate also resonated on the state level, with Jindal and several other Republican governors announcing that they would not move to implement parts of the law until after the election, in hopes that Obama would lose and the act could be repealed.

“We’re going to do everything we can here in this swing state to help elect a new Senate and help elect a new president in four months,” Virginia Gov. Robert McDonnell said during the RNC conference call.

But swing-state Democrats said they would not shy away from engaging the GOP and did not fear losing votes among independents who might be cool to Obama’s legislation.

“It’s going to be a great issue anytime you have such a clear contrast,” said Chris Redfern, Democratic Party chairman of Ohio, where Obama will launch a two-day bus tour next week. “Our side is standing up for breast cancer survivors and young people who have lost a job and do not have health care.”

Democrats also said they would continue to remind voters that Romney, while governor of Massachusetts, authored a health-care law that was the template for Obama’s legislation and included a penalty for those who choose not to purchase health care.

That will make it difficult for Romney to embrace the Republican attack line that the law represents a tax increase, Democrats said. On the campaign trail, Romney has called the legislation a “job-killer,” hoping to wrap health care into his overall message on the economy.

“I think people recognize that if you want to replace Obamacare, you’ve got to replace President Obama, and the urgency of doing that is galvanizing people across the county,” Romney said at a fundraiser in New York on Friday. “You look at his policies and ask whether they are helping the economy and helping the recovery or hurting it.… This piece of legislation, does it help create jobs or does it kill jobs? Ask employers, ask small employers in particular.”