President Barack Obama won a major victory on his health care overhaul from the Supreme Court on Thursday, but Democrats were the first to try to change the subject, as both parties gauged the political implications for the elections.

Republicans, who were briefly stunned by the decision, quickly seized on it as a rallying cry for November — and the need to replace not just the law but also Obama and the ruling Senate Democrats.

House Republicans announced within an hour of the court’s decision that they would hold a vote on July 11 to repeal the law.

Behind the scenes, Democrats at the White House and on Capitol Hill hugged in celebration of the court’s decision to uphold the bulk of the law. But the momentary joy didn’t dispel the fact that the law remains unpopular nationally. And while Obama and other Democrats paused Thursday to give thanks for the decision and highlight the popular benefits in the law, they also immediately sought to shift the conversation back to jobs and the economy.

Republicans initially were surprised by Chief Justice John Roberts’ alliance with the court’s four liberal justices to uphold the law. Roberts, nominated by President George W. Bush in 2005, has been a darling of conservatives but ruled that the law’s penalty for not buying insurance was constitutional as a tax.

But the GOP quickly regrouped, accusing Obama of misleading the public on the issue and of endorsing a tax increase on middle-income Americans, and they pivoted back to their message that the law must be repealed.

“We pass plenty of terrible laws around here that the court finds constitutional,” Senate Minority Leader Mitch McConnell (R-Ky.) said. “There’s only one way to truly ‘fix’ Obamacare, and that’s a full repeal.”

Obama and presumptive GOP presidential nominee Mitt Romney dueled in back-to-back statements on television.

Acknowledging the political downsides, Obama ticked off the popular benefits in the law while arguing again for the individual mandate at its heart.

“It should be pretty clear right now that I didn’t do this because I believed it was good politics,” he said. “I did it because I believed it was good for the American people.”

Obama noted that Romney came to the same conclusion in Massachusetts. A law signed by Romney as governor of that state charges residents a tax penalty of up to half the cost of a health insurance plan if they don’t buy one.

Above all, Obama called on the country to move on.

“It’s time to move forward” and deal with the pressing issue of the day — the economy, he said.

Romney again vowed to act to repeal the law the day he takes office.

“This is the time of choice for the American people. Our mission is clear: If we want to get rid of Obamacare, we’re going to have to replace President Obama,” he said.

Speaking to reporters from a Washington, D.C., office building with the Capitol Dome in the background, Romney called the Affordable Care Act a $500 billion tax increase and argued it would depress job creation, increase the deficit and give too much control to Washington.

Romney said he would “repeal and replace” the health care law with legislation that maintains the current statute’s prohibition against refusing coverage based on pre-existing medical conditions and ensuring that people could keep the insurance they currently have, if they so choose. Romney hasn’t been specific on how he would accomplish those ends.

But in a theme likely to continue through November, senior Obama administration officials noted that Romney was the architect of the tax penalty, and they said the tax penalty in Massachusetts is more onerous than the one in Obama’s overhaul. They suggested that less than
1 percent of the public would end up paying the national penalty and argued that many more Americans would actually be getting a tax cut in the form of tax credits to buy health insurance.

While House Republicans announced their plan to hold a repeal vote, Senate Democrats said they will bring up Obama’s proposed business tax cut package after the July Fourth break.

“The Supreme Court has spoken, the matter is settled,” Reid said at a press conference with Democratic leaders. “With millions of Americans still struggling in this tough economy, we can’t look back, we need to look forward.”

Obama and Reid also suggested that they would be open to improving the law, but Reid was clear that any effort would have to wait until after the elections.

Democrats hope that their narrowly tailored approach highlighting the particular, and popular, benefits of the health care law will eventually gain traction, even as they have had trouble ginning up support for the law as a whole and the mandate in particular.

Senate Majority Whip Dick Durbin (D-Ill.) said the approach Democrats have taken in the lead-up to the court’s decision could continue through November.

“When you get into specifics, people say, ‘Yes! My 25-year-old can be covered on my family policy’ and ‘My baby with an asthmatic situation can’t be denied health insurance,’” he said. “Those are real-world life experiences people can relate to.”

Senior administration officials also suggested that they don’t expect polling on the issue to change much one way or another in the wake of the decision; nor will Obama make a major new effort to sell the issue beyond what he has already done. A recent ABC News/Washington Post poll showed 52 percent of respondents viewed the law unfavorably.

Still, the officials suggested the public will not be eager to have another nasty Washington fight over the issue, which they said is what would happen next year if Romney is elected.

Politics aside, Democrats were bucked up by the decision.

“The psychological impact of a Supreme Court decision saying this law is constitutional is a positive thing for those of us who supported it and especially for the president,” Durbin noted.

An air of relief shrouded the Senate Democrats’ weekly Thursday lunch, with leaders taking a victory lap after the closed-door session. The general sense is that Democrats now feel free to move on from the health care issue, even though Republicans are poised to make that difficult.

Already, Democratic leaders were stumbling Thursday when asked about the ruling that the mandate was a tax — an argument that was quickly becoming a GOP talking point.

When asked whether he thought it was a tax, Reid demurred and said he was no constitutional law scholar. Sen. Charles Schumer (N.Y.), who heads the Democrats’ communication and policy arm, also sidestepped the question.

Senate Republicans are already considering ways they can repeal the bulk of the law next year via the budget reconciliation process, which would need just 51 votes, said Senate Republican Conference Chairman John Thune (S.D.). Of course, that plan assumes the GOP wins enough seats in November to take control of the chamber and pass a budget.

“That is not something necessarily we’ve given a lot of consideration to yet, but we are definitely going to make every attempt — hopefully with a new president and a majority in the Senate — to repeal the law and replace it with common-sense reforms that actually do lower costs for most Americans,” Thune said of a reconciliation bill. And he noted that there could be a political silver lining.

“With regard to the politics, I do think it provides great clarity in the fall campaign,” Thune said. “We’ve said all along that irrespective of what the court says we perceive this to be really bad policy and we will take that case and that argument to the American people.”

But Schumer said he thinks the Democrats now have the upper hand politically.

“The longer they talk about wanting to repeal health care instead of focusing on jobs and the economy and the middle class, the harder it’s going to be for them to ever get that majority,” Schumer said after the press conference.

David M. Drucker contributed to this report.