Editor's Note: (Jeffrey Toobin is CNN's senior legal analyst and author of "The Oath: The Obama White House and the Supreme Court." The opinions expressed in this commentary are solely those of the author.)
(CNN) CNN's senior legal analyst Jeffrey Toobin offers his reaction to the Supreme Court's 6-3 decision that turned back a challenge to President Barack Obama's signature legislative achievement.
Is the Supreme Court's ruling in King v. Burwell a surprise?
Toobin: It's a surprise that it was such a sweeping and overwhelming victory for the Obama administration. The Affordable Care Act will only be overturned if Congress does it, but remember that the President retains the veto pen. So the issue is now closed for at least the next year and a half until there's a new President in the White House.
What does it mean to Americans?
Toobin: In very practical terms, 6.4 million people will keep their federal tax subsidies so they can buy health insurance. That's hugely important. Even more, if the subsidies had disappeared, it's possible that there would have been a death spiral of lost subsidies, lost customers, rate increases and dismantling of the law.
What does it mean to the Obama presidency?
Toobin: This is the President Barack Obama's major achievement and it is now here to stay. It's the biggest moment of his second term.
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What do the ruling and the reaction to it tell us about the Court -- particularly Chief Justice Roberts?
Toobin: The case put Roberts on the spot with the Republicans who were his most ardent supporters and who opposed Obamacare. But I think it shows that Roberts was (a) a down-the-middle judge and (b) the case was a pretty easy one at the end of the day. Not a single member of Congress supported the plaintiff's interpretation of the law during the congressional debate over Obamacare; it's hard to imagine the court would have imposed that view after the fact.
Why does a court with a conservative majority wind up disappointing conservatives as often as it has?
Toobin: This remains a conservative court. Just recall the rulings undermining the Voting Rights Act and on Citizens United and all the other decisions deregulating American politics. But Roberts is an establishment conservative who is not interested in throwing millions of people off health care until the law genuinely compels it. As for same-sex rights, it's really just Anthony Kennedy's court -- he has joined with the liberals on gay rights issues for years, and he's responsible for that entire area of the law. Kennedy was also part of the majority that upheld subsidies--and he is also an establishment conservative.
Was the court's ruling as much about politics as the law?
Toobin: The Supreme Court is always a deeply political institution as well as a legal one. It's impossible to decide the kind of issue the justices address in a non-political way. They are deeply political, and the mix of politics and law has always been part of what the justices do.
'Jiggery-pokery': The best lines from Antonin Scalia's Obamacare dissent
In his dissenting opinion, Justice Antonin Scalia said "We should start calling this law SCOTUScare." What did he mean?
Toobin: He meant that the law was being improperly propped up by the high court when the law didn't justify it. As usual, Scalia was pithy and funny, but as is often the case, he was in the minority.
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