I’m stunned.

The Supreme Court, moving back into the deep controversy over the new health care law, agreed early Friday afternoon to decide how far the federal government can extend its program of subsidies to buyers of health insurance.

All diligent conservative blog readers know about the Halbig case by now, yes? I’ve written at least three posts about it so I won’t rehash the basics. Follow the links here if it’s new to you. It was a Category Five ObamaCare tornado in July when a three-judge panel on the D.C. Circuit agreed with conservatives and ruled that the text of the O-Care statute does not allow subsidies for people who bought their policies on the federal exchange, i.e. Healthcare.gov. Only if you bought your policy through an exchange created by a state are you eligible for help from Uncle Sam. That ruling is a nuclear bomb for the White House, obviously, because it would mean that the vast majority of new enrollees in O-Care would suddenly be on the hook for the full cost of their premiums. That would prove too expensive for many of those people, which would mean lots of dropped coverage and total chaos in the insurance industry. The D.C. Circuit ruling was huge, especially since the Fourth Circuit ruled the opposite way in a similar case decided the very same day as Halbig. That meant a circuit split. And the Supremes almost always take appeals where there’s a circuit split in order to resolve the dispute and set one uniform interpretation for all federal courts.

But then, six weeks later, the Halbig ruling went out the window. The full D.C. Circuit decided to rehear the case en banc, meaning that the three-judge panel’s ruling was no longer good law. Since the full court has more liberals than conservatives, it was a cinch that they’d overrule the panel and declare that federal O-Care customers were eligible for subsidies after all. Worse yet, once they did, it would mean there was no more circuit split. The conservative Supreme Court would no longer feel compelled to take the case, so they’d probably pass on it. And the Halbig line of attack on ObamaCare would be down the drain.

That’s why today’s granting of cert is a bolt from the blue. They’ve decided to trump the D.C. Circuit’s liberals by taking the case anyway, making the en banc hearing moot. ObamaCare fans are mortified:

Timothy Jost, a professor at the Washington and Lee University School of Law and supporter of the law, told Business Insider the law is now in “very dangerous territory.”

“This is highly unusual. The Supreme Court doesn’t usually just take away cases from circuit courts where there’s no circuit split, which I think sends a signal that politics might be driving this — not legal analysis,” Jost said. “So I think that’s bad. It doesn’t look good that this could be a politically driven decision.”

The big mystery: Which four justices voted to grant cert? There’s no way to know since the Court doesn’t release that information so we have to guess. It stands to reason that it wasn’t any of the Court’s liberals: With the D.C. Circuit set to overrule the three-judge panel, why would they tempt fate by voting to give the Supremes’ five conservatives a chance to wreck ObamaCare? It had to be four justices from the conservative wing. And I agree with Benjy Sarlin: It seems highly unlikely that John Roberts, having taken withering fire from the right in finding the mandate constitutional two years ago before O-Care launched, would now turn around and nuke the law a year after implementation based on a dispute over statutory construction, with millions of people’s coverage hanging in the balance. Roberts probably wanted no part of this. So odds are it was Scalia, Thomas, Alito, and Kennedy(!) who pulled the trigger, and now Roberts is in the hot seat again. Will he double down by saving ObamaCare a second time? Or will he effectively destroy the law by ruling that subsidies for federal consumers are illegal?

Wow. Stand by for a few updates.

Update: An alternate take on Roberts’s thinking:

Update: You’ll hear lots of people today say that the Supremes agreed to hear the Halbig case, but technically speaking that’s not true. It’s the Fourth Circuit’s ruling in favor of ObamaCare that they’re hearing, not the D.C. Circuit’s Halbig ruling. There’s no practical difference, though. Obviously, the Supremes aren’t going to defer to the lower court’s ruling in a case this momentous.

Update: The silver lining here for ObamaCare supporters, of course, is that this could end up being a giant sh*t sandwich for the new GOP Congress and, more importantly, America’s new Republican governors and state legislatures. If Roberts sides with conservatives and finds that the law, as written, says federal consumers aren’t eligible for subsidies then the pressure on Congress to re-write that part of that law so that they are eligible will be intense. Boehner and McConnell will dry-heave over the electoral implications of it in 2016, but they’ll resist because they know their base would revolt if they rescued O-Care by rewriting that law. So the pressure will shift to the states to quickly build their own exchanges, whose consumers are eligible for subsidies. If you’re a Republican legislator or governor facing voters angry that they lost their subsidies because of the Supreme Court, what do you do then?

Update: Yup.

Reid nuked the filibuster for lower-court nominations precisely because he wanted to get a bunch of liberals confirmed to the nation’s appellate courts, starting with the D.C. Circuit. That strategy was about to pay off when the liberal en banc court overturned the three-judge panel on Halbig. Instead, this.