WASHNIGTON—The Affordable Care Act survived the U.S. Supreme Court, but Republicans are growing more determined to make sure it doesn't survive the November elections.

Republicans in Georgia and elsewhere said Thursday's ruling preserving President Barack Obama's signature domestic achievement has further energized them to elect Mitt Romney as president and pick up at least three Senate seats to tip the balance of power to the GOP.

"Everything now is dependent upon a President Romney, and the American people — and especially our base — needs to understand that," said U.S. Rep. Phil Gingrey, a Marietta Republican.

Congressional Republicans focused Friday on how they might be able to repeal the Affordable Care Act. But the law may prove even more difficult to undo than it was for Democrats to pass in 2010 over strenuous Republican objection.

Meanwhile, the presidential campaigns used the ruling to raise campaign money and try to appeal to voters.

On Friday, Romney said the court's 5-4 ruling gave his campaign to defeat Obama "greater urgency."

"I think many people assumed that the Supreme Court would do the work that was necessary in repealing Obamacare," Romney said, adding that the court "did not get that job done."

Some Republicans pounced on the reasoning behind the Supreme Court ruling — that the mandate that all individuals buy health insurance is a tax to appeal to voters.

"Those who will end up paying the heaviest burden for not buying government-mandated insurance won't be the wealthiest Americans, but the very middle class famiilies the president claims to defend," said Senate Republican leader Mitch McConnell of Kentucky.

Presidential press secretary Jay Carney responded that Obama has repeatedly signed legislation cutting middle-class taxes, and that Republicans want to extend existing income tax cuts for the wealthy and then add "another $5 trillion ... that would disproportionately benefit" the same group.

Congressional Republicans used Friday to start forming plans to repeal the health care law. Key to those plans is regaining control of both the White House and Congress.

Romney has said that if elected, he will immediately grant states waivers from the law, then work with Congress to repeal it.

Republicans, who now have 47 votes in the Senate, believe that if they can gain a simple majority in the Senate through the November election, they have an antidote to a likely Democratic filibuster. Instead of having to get 60 votes to beat a filibuster and repeal the law, they would attempt to use the budget reconciliation process, which requires only 51 votes. But that tactic is no sure thing because it only applies to legislation that involves spending or revenue and does not increase the deficit.

Whether it meets those conditions depends on two nonpartisan factors outside the GOP's control — the Senate parliamentarian and the Congressional Budget Office — said Sarah Binder, a political science professor at George Washington University who has written several books on Congress. The parliamentarian has final say on whether a section alters the governmental balance sheet, and the CBO determines the impact on the deficit.

"It certainly strikes me as plausible, but the issue really is ... how it's crafted," Binder said. "The issue with reconciliation is, simply, it's not just a catch-all vehicle that you are awarded this 51-vote majority and you use it to push through whatever you want. ... It's designed to affect revenue and spending."

Created in a 1974 law, the reconciliation process has been employed by both parties to pass bills overseeing fiscal policy.

Foes of the health care law say that creating a new health insurance subsidy will drive up the national debt in the long term. But the CBO ruled it reduces deficits, as it judges laws over a 10-year period.

That could change, though, with the Supreme Court ruling that states can choose not to expand their Medicaid programs. The CBO will release a recalculation in the coming weeks, and the ruling will probably shift some costs to the federal government.

Binder said the reconciliation route could be difficult because there is much in the Affordable Care Act that has no impact on government revenue and spending.

But Republicans said that by ruling that the individual mandate is a tax, the court gave its reconciliation plans additional ammunition.

"That makes it a whole different ballgame," said U.S. Sen. Johnny Isakson, R-Ga.

Also in the GOP's favor is the fact that Democrats used reconciliation to put the finishing touches on the law. After Republican U.S. Sen. Scott Brown took over the Massachusetts seat of the late Sen. Edward Kennedy in January 2010, Democrats lost their 60-vote majority.

The Senate and House already had passed different versions of the law, but Senate Majority Leader Harry Reid was able to use reconciliation to pass changes to the law that the House approved as well.

"Since the precedent of using [reconciliation] to enact [the Affordable Care Act] is so recent, it would be hard to argue against its use" for repeal, said Ross Baker, a political science professor at Rutgers University.

Some Democrats had hoped the ruling would blunt the GOP's determination to scrap the law.

"I think it will cause our Republican friends in the House to take a second look at health care," Rep. David Scott, an Atlanta Democrat, said minutes after Thursday's ruling, foreseeing cross-aisle partnerships on issues such as medical malpractice reform.

But it took just hours for House Republicans to schedule another vote to repeal the law for July 11. Friday morning, members of the House GOP Doctors Caucus met with Romney health policy adviser Avik Roy. They discussed what they view as the law's shortcomings and ways to exploit them with the voting public, as well as the prospects for a reconciliation repeal in a Republican Senate.

Asked about Scott's comment after the meeting, Gingrey — the chairman of the doctors caucus — made clear that Republicans are not backing down.

"That's like saying, 'Now that I've cut your head off let's bury the hatchet,' " he said. "I don't think we can come together on that. It's too big a deal."

The Associated Press contributed to this article.