This may seem a little technical, but it is not a minor matter. A number of politicians and commentators are claiming that the Supreme Court in the Obamacare case “limited” the reach of the commerce clause, i.e., five justices held that individuals cannot be mandated to buy insurance under the commerce clause. Actually, the five justices did not limit anything. They simply did not accept the Obama administration’s ridiculous argument that inactivity is commerce. The status quo stands because Obamacare was upheld under the tax provisions. However, the bigger point is this — when a court issues an opinion, it is said to be the “Opinion of the Court.” The Opinion of the Court is the controlling precedent. Chief Justice Roberts wrote the Opinion of the Court for Parts I (background on the Obamacare law), II (the Anti-Injunction Act is not a bar to the lawsuit proceeding and being decided) and III-C (Obamacare is valid under the tax power).
But respecting Part III- A, the commerce clause and necessary and proper section, the decision notes that Roberts is writing for himself, not for a majority. Furthermore, the Dissent is labeled as: “Justice Scalia, Justice Kennedy, Justice Thomas, and Justice Alito, dissenting.” It is not labeled as “dissenting in the judgment, concurring in part” or some permutation.
You cannot say it was the “opinion of the court” that the mandate violated the commerce clause. You have to cobble together sections where Roberts is writing for himself and the dissent (which did not formally join with Roberts), is writing for itself.
In fact, Justice Thomas, in his separate dissenting opinion, wrote:
“The joint dissent and THE CHIEF JUSTICE correctly apply our precedents to conclude that the Individual Mandate is beyond the power granted to Congress under the Commerce Clause and the Necessary and Proper Clause.”
Notably, this does not explicitly state that the dissenters joined with the Chief’s opinion respecting the commerce clause. If five justices had intended for their view of the commerce clause to be controlling as the majority view of the court, they would have said so by joining or concurring in each others’ parts. They didn’t. There was no formal majority on the commerce clause issue. Should this matter come before a court again, it is not settled as a matter of precedent and no doubt the litigants will still be fighting over it.