The decision also gives states more wiggle room in how to implement the law by making Medicaid expansion voluntary. The court struck down a portion of the law that would have forced states to accept a major expansion of Medicaid to all Americans earning up to $30,733 for a family of four or risk losing all federal funds under the program.
Roberts called that part of the Affordable Care Act "a gun to the head" by threatening as much as 10% of states' budgets. But states also will be required to comply with the rest of the act, such as by setting up insurance exchanges; only 15 states have done so already.
A uniform pace of action in the states is unlikely. Some governors hailed the decision as an affirmation of changes they have made already. Others called it a misguided ruling and said they would comply only begrudgingly.
Michigan Gov. Rick Snyder, a Republican, said his state would create a health insurance exchange. But the law, he said, "misses the point on the most important reforms needed in our health care system": cost controls.
Clement, the states' lawyer, acknowledged that their victory in court on the Medicaid language might prove Pyrrhic. Because new federal Medicaid funds will "come from the federal tax revenues that are imposed on all 50 states," Clement said, "there's still going to be real practical incentive for them to take the new money."
Not all of them will, predicted David Merritt, a senior adviser at Leavitt Partners, a health consultancy headed by former Republican secretary of health and human services Michael Leavitt. While the federal government initially will pay for the Medicaid expansion, cash-strapped states eventually will have to kick in at least 10% of the cost.
"Long term, they're going to be on the hook," Merritt said. "They're not going to be on the hook for a lot, but any amount is huge when you're broke."
Next stop: Voting booths
In the wake of the decision, Republicans had one message: November has never been more important. Romney, GOP officials and strategists said the ruling only raised the stakes for the 2012 election and would provide the fuel needed to get their most enthusiastic supporters to the polls.
"What the court did not do on its last day in session I will do on my first day if elected president of the United States," Romney said in a four-minute statement at a building across from the U.S. Capitol. "I will act to repeal Obamacare."
His effort received an immediate fundraising boost. By late afternoon, spokeswoman Andrea Saul tweeted that the campaign had raised $2.5 million in the wake of the ruling. And in those hours, the National Republican Congressional Committee— the party's House campaign arm — issued a series of e-mails that said the health care law would become permanent unless many Democratic incumbents are "replaced" in the fall.
Republican strategists said the Supreme Court decision made sure the GOP's conservative base would be out in full force.
The conservative group Americans for Prosperity announced it would launch a $9 million television advertising blitz Friday in 16 states to highlight opposition to the law.
Within an hour of the decision, Majority Leader Eric Cantor, R-Va., said the House would vote on a repeal of the law July 11. Nothing new there: The House has voted 30 times already to repeal parts or all of the law, but the measures have gone nowhere in the Democratic-controlled Senate.