From the sound of conservatives, Thursday was a day that will live in infamy. The Supreme Court decision upholding Obamacare unleashed a storm of outrage from critics who made it sound like a combination of Pearl Harbor, the Great Depression and the Black Plague.

"We are now becoming Venezuela and on the way to becoming Castro's Cuba," said radio talk show host Michael Savage. My favorite came from a Tea Party organization: "The hideous abomination from hell must be eradicated."

Well, that's one way to look at it. Another way is for advocates of limited power, individual freedom, and constitutional government to count all the ways in which our side won.

When Congress approved the requirement that everyone have health insurance, it took for granted it could legislate at whim, courtesy of the commerce clause of the Constitution. That provision has consistently been given a broad interpretation—allowing the federal government, for example, to force a farmer to destroy wheat he grew not to sell (commerce) but merely to eat.

When Georgetown University law professor Randy Barnett challenged the mandate, legal scholars laughed out loud. He insisted the clause allowed regulation of economic activity, but not of economic inactivity—such as declining to buy health insurance. This step, he said, was literally unprecedented.

One legal scholar predicted Barnett would lose 8-1. The White House said the argument "shouldn't be given too much credence in the press." Asked about the constitutionality of the mandate, then-House Speaker Nancy Pelosi replied, "Are you serious? Are you serious?"

Yet, lo and behold, the argument prevailed with a majority of justices. "The framers gave Congress the power to regulate commerce, not to compel it," explained Roberts. "The commerce clause is not a general license to regulate an individual from cradle to grave."

Yes, the court did narrowly uphold Obamacare as a permissible exercise of Congress' taxing power. But if it was going to uphold it, this was the least dangerous method. Allowing it under the commerce clause would have amounted to an open-ended grant of power.

What tangible difference will this limitation make in future cases? It's not clear yet. But Yale law professor Akhil Reed Amar, who supports the program, glumly told The New York Times, "Federal power has more restrictions on it. Going forward, there may even be laws on the books that have to be re-examined."

While it was upholding the mandate, the court was striking down an equally important part of the law: the requirement that states greatly expand Medicaid coverage, at a cost of about $1 trillion between 2014 and 2022. The administration sought to force states to go along by threatening to take away all their Medicaid funds—not just those provided for the expansion. But Roberts and Co. said no.

Does it matter? You bet. It's the first time the court has ever said Washington went too far in the conditions it places on money sent to state governments. The ruling will give states more latitude to make their own decisions in all sorts of areas.

The case also registered a victory for the notion that judges should apply the Constitution in an impartial way rather than simply impose their policy preferences. George Washington University law professor Orin Kerr, writing on the conservative-libertarian blog The Volokh Conspiracy, said the overall decision was "a largely conservative opinion that just happens to get to a liberal result."

Equally significant is that it took a worse health care option off the table. The irony of the challenge is that if Obamacare had been struck down, supporters of universal health coverage would have been left with no good option but a "single-payer" system, also known as "Medicare for all"—which is undoubtedly constitutional.

Whatever the flaws of Obamacare, it at least builds on the existing system of private insurance. Vermont's self-proclaimed socialist senator, Bernie Sanders, used the court's decision to renew his call for a single-payer system. But for him, the verdict was the worst thing that could have happened.

For anyone even slightly open to evidence, letting Obamacare take effect will provide an illuminating experiment in how to afford the miracles of the American medical system to more people, including many in dire need. It may be a failure, or it may be a success. But it will not be uninformative.

Steve Chapman blogs daily at newsblogs.chicagotribune.com/steve_chapman.