Speaking at the White House, President Obama declared the Supreme Court ruling on health-care subsidies a win but said there is still work to be done. Here are key moments from his reaction to the ruling. (AP)

I won.

That was the message President Obama had for Republicans and other opponents of the Affordable Care Act following the Supreme Court's 6 to 3 ruling Thursday that upheld the use of subsidies in the federal marketplace created by Obamacare.

"Today after more than 50 votes in Congress to repeal or weaken this law, after a presidential election based in part on preserving or repealing this law, after multiple challenges to this law before the Supreme Court, the Affordable Care act is here to stay," Obama declared in a Rose Garden appearance less than two hours after the court handed down its opinion. 

It's hard to argue with Obama's triumphant tone. The court's ruling Thursday amounted to the final, major attempt by opponents of the law to invalidate all or part of it. Those attempts — ranging from more than four dozen votes to repeal the law by the Republican-controlled House, a 2012 election fought on the law and a previous court challenge on the constitutionality of the individual mandate — amounted to one of the longest and trickiest political and legal gantlets run in modern American politics.

Yes, there are more challenges to the law to come — most notably one brought by House Speaker John Boehner, who pledged Thursday to continue his efforts to get rid of Obamacare.

But the simple truth is that this was widely regarded as the last, best chance to knock the law down in a meaningful way.

Politically speaking, most Republican strategists and even most GOP politicians have privately acknowledged for quite some time that the chances of ripping the law from its roots legislatively was a nonstarter for two reasons. First, with Obama in the White House, he would veto any measure that would substantially change the law that bears his name. Second, the longer the law is, well, the law, the harder it becomes to drastically change it. Whether or not people initially liked Obamacare, they have begun to get used to it. Trashing the law in place of something else — that would, inevitably, have its own set of issues and problems — becomes a harder sell every day it remains law.

With its decision to uphold a key Obamacare provision, the Supreme Court cemented President Obama's legacy, says The Post's Chris Cillizza, and in a way let Republican presidential candidates off the hook. (Tom LeGro/The Washington Post)

Given that, the only route to invalidation or major overhaul of Obamacare in the minds of savvy Republicans was through the courts. That first took the form of the case dealing with the individual mandate. When that was lost, most anti-ACA forces rallied to the Burwell case, which was decided today. Now, whether they want to admit it or not, a significant amount of the air has come out of their balloon. "The huge life and death cases [related to the law] have pretty much run out," concluded NBC's justice correspondent Pete Williams.

The law can and will be an issue in the 2016 presidential election, particularly given Hillary Clinton's immediate embrace, literally, of the decision Thursday.

Already many Republicans are seeking to drive the remaining energy aimed at getting rid of the law toward next November — insisting that now, controlling the presidency is the only way to make fundamental changes to it. Here's Jeb Bush, for example, in the wake of the court decision: "I will work with Congress to repeal and replace this flawed law with conservative reforms that empower consumers."

And that might well work, as the base of the Republican Party remains deeply unhappy about the ACA. And we've already seen how being identified as the most ardent opponent of the law has helped boost Texas Sen. Ted Cruz (R), not only into the 2016 presidential race but close to its top tier.

But in a general election context, that will be a far harder sell. Why? Because Clinton will now be able to make the very strong case that the law has been fought judicially, legislatively and through campaigns and, in each instance, has survived those challenges. "This is old news," you can hear Clinton saying. "The Affordable Care Act is the the law of the land. I know some Republicans might not like that, but the fight is over."

Republican presidential candidate Jeb Bush responds to the Supreme Court's decision to uphold the Affordable Care Act in King v. Burwell. (YouTube/Jeb Bush)

That's a compelling argument, especially to voters not closely affiliated with either party who are likely to be swayed by the sheer amount of validation Clinton can point to regarding the law.

All of that, of course, is a bit down the road. For today, Obama — after five years of efforts that cost his party control of Congress and inflicted deep down-ballot losses — has seen the law that bears his name and that will be his signature policy legacy, no matter what he does in the remainder of his second term, validated in a massively high-profile way.

"This is health care in America," Obama declared Thursday.

He's right.