As a conservative, he is as appalled as his conservative colleagues by the administration’s central argument that Obamacare’s individual mandate is a proper exercise of its authority to regulate commerce.

That makes congressional power effectively unlimited. Mr. Jones is not a purchaser of health insurance. Mr. Jones has therefore manifestly not entered into any commerce. Yet Congress tells him he must buy health insurance — on the grounds that it is regulating commerce. If government can do that under the commerce clause, what can it not do?

“The Framers . . . gave Congress the power to regulate commerce, not to compel it,” writes Roberts. Otherwise you “undermine the principle that the Federal Government is a government of limited and enumerated powers"....

the ultimate finesse...  manages to uphold the law, but only on the most narrow of grounds — interpreting the individual mandate as merely a tax, something generally within the power of Congress.

Result? The law stands, thus obviating any charge that a partisan court overturned duly passed legislation. And yet at the same time the commerce clause is reined in. By denying that it could justify the imposition of an individual mandate, Roberts draws the line against the inexorable decades-old expansion of congressional power under the commerce clause fig leaf.

Law upheld, Supreme Court’s reputation for neutrality maintained. Commerce clause contained, constitutional principle of enumerated powers reaffirmed.