Nearly all the experts predicted it would wind up a 5-4 decision and that Anthony Kennedy would be the swing vote. They got it half right.

Nobody saw this coming.

Chief Justice John Roberts joined the Supreme Court’s four liberals Thursday to uphold the linchpin of President Barack Obama’s plan to expand health coverage to nearly all Americans, a surprise conclusion to a constitutional showdown.

The ruling clears the way for the biggest revamp of America’s health-care system since the 1960s—and sets the stage for a renewed political fight over its merits.

By a 5-4 vote, the court held the law’s mandate requiring Americans to carry health insurance or pay a penalty valid under Congress’s constitutional authority to levy taxes.

They were allegedly going to rule on whether it could be upheld under the Commerce Clause, and they did. The majority said it couldn’t. But Justice Roberts swung in another direction.

Chief Justice Roberts went on to say that the penalty for failing to carry insurance met the criteria for a tax.

Not even the White House prepared for that.

In fact, the high Court decision upholding the mandate as a taxing provision counters how President Obama has described the mandate in the past. The fact is that President Obama refused to frame the health care mandate as a tax during an interview with ABC News in 2009. The President flatly rejected the assertion that the penalty for not purchasing health care insurance should be characterized as a tax. “I absolutely reject that notion,” the President said.

So that’s likely going to be an issue in this presidential election year. A big one, given the size of this tax increase, coming from a president who has relentlessly insisted he would never raise taxes on the middle class. There’s no denying it’s a tax now.

And it may recharge the Tea Party coalition that helped Republicans take control of the House of Representatives in November 2010 on the staunch promise of not raising taxes and not compromising with anyone who proposed to for any reason. Maybe they’ll coalesce around Mitt Romney now that his election is the only way to stop the Obamacare juggernaut that will de facto tax Americans to pay for it. Who knows, this is day one and things have just changed. Dramatically.

Not only did no one see this coming, the White House, Democrats in and seeking office and the liberal media have been trying different strategies in the days and weeks leading up to the Supreme Court ruling to deflect what seemed like an inevitable setback for Obama. The New York Times ran a front page story, above the fold, on the justices dropping in public opinion polls lately, which seemed odd given that they’re the one body that doesn’t answer to the public.

Then that strategy turned to the more recent one of discounting the outcome before it happened, with news stories claiming Obamacare would still be significant reform no matter what the justices decided.

Then there was this, which was interesting. Especially read a day later.

It also was not the result some liberals and Democrats expected before the decision was unveiled this morning.

Little more than 12 hours earlier, the Senate candidate for whom Obama campaigned in Boston on Monday – fellow Democrat Elizabeth Warren – was on MSNBC saying the ruling would be a telling gauge for assessing the politicization of the Supreme Court.

“We need to use this moment to reflect on the importance of the Supreme Court and who sits on the Supreme Court,” Warren told liberal talk show host Rachel Maddow…

“The Supreme Court is wading into really deep waters, and is doing it in ways that, I think, worry us all, and I think it’s a reminder that who sits in the United States Senate, to review those nominations, to vote on those nominations, really does matter,” said Warren.

For emphasis, she added: “It will be about the Affordable Care Act tomorrow, but it will also be about the Supreme Court tomorrow.”

Yes, it sure was. About both. What are they saying now about the Supreme Court? About judicial activism, and the vetting of nominations? About the Affordable Care Act being a huge tax on Americans after all?

Stay tuned. There will be plenty. For starters, the focus moves to the Senate, where Harry Reid is asking everyone to move on now to something else.

And meanwhile, the HHS lawsuits move forward. While the Supreme Court ruling didn’t affect those suits, some justices gave dropped some loaded cues into their opinions that the tax for this healthcare still has to respect constitutional requirements, like “the free exercise of religion” to name one. More lawsuits sure to follow.