Let's start by all agreeing that this is a question that only lawyers can love and that it only matters to the extent that a majority of an appellate court, say, for example, the U.S. Supreme Court, values precedent. Okay? Okay. So what was the holding in National Federation of Independent Business v. Sebelius about the Commerce Clause? There's a great debate underway at Volokh Conspiracy, sparked by a Washington Post op-ed by the father-of-the-anti-Commerce-Clause-argument-against-Obamacare, Randy Barnett. Barnett wrote that the opinion "represents a fundamental departure from how most law professors viewed constitutional law before Thursday," and explains:
So, if we prevailed on all our arguments about economic mandates, how could the Affordable Care Act be upheld? Roberts accomplished this by rewriting the law’s “individual responsibility requirement” so that it was no longer a mandate but merely an option: get insurance or pay a mild “tax” penalty. Contrary to the statute, he ruled that anyone who did not have to pay the penalty would have no legal duty to get insurance. So, because there is no mandate, the tax penalty is constitutional.
In perhaps the most important passage of his opinion, Roberts insisted that “without deciding the Commerce Clause question, I would find no basis to adopt such a saving construction” of the penalty. This makes his analysis of the commerce clause a binding holding for future courts to follow.
Barnett's fellow VC blogger David Post will have none of it. He wants dicta to be carved out from the holding based on what was necessary to reach the holding, regardless of what the opinion itself says its holding includes:
A court’s holding defines the scope of its power; holdings must be obeyed, by citizens and by other (lower) courts. Dicta is the stuff that doesn’t have to be obeyed. Saying “just look at how the Court itself defined its holding” is like saying: “Just let Congress decide on the scope of its powers.” Courts cannot be allowed to define the scope of their own power because if they are, they’ll do what all institutions do when allowed to define the scope of its own power: expand it unmercifully. Of course Roberts and the 4 Justices who are with him on this question would like it to be called a “holding”! They think they’re right, and they’d like to have their view on the matter obeyed by others. But the holding/dictum distinction prevents them from doing that, over and over and over again. Courts don’t have to be obeyed when they propound on something they didn’t have to propound upon for the purpose of deciding the case the way they decided it. To decide that the mandate is within Congress’ taxing power, they didn’t have to decide that it is not within its Commerce Clause power.
Under this view, he concludes:
I don’t think Roberts’ analysis of the Commerce Clause is binding on future courts, because it is non-binding dicta — notwithstanding Roberts’ attempts to declare it otherwise.
Here’s the simplest way to describe what happened in this case: five Justices held that the individual mandate provisions of the Affordable Care Act are within Congress’ Article I taxing powers. Roberts also expresses his opinion (in part IIIA) that the mandate is not within Congress’ powers to regulate interstate commerce. It’s also (presumably) not within Congress’ power to coin money, or to raise an army, or provide for a Post Office — though none of the Justices mentioned any of that. They didn’t mention any of that because it was not necessary to the court’s judgment in the case that the mandate is constitutional) — the very definition of non-binding dicta.
Roberts tries to declare it otherwise (in the language Randy quotes):
“without deciding the Commerce Clause question, I would find no basis to adopt such a saving construction” of the penalty.
This makes little sense to me – other than as a rhetorical ploy to try to convince readers to treat it as a binding holding.
In response, VC blogger Ilya Somin calls the dictum/holding issue a "mess" and proposes a "simple solution" -- taking the Court at its word and allowing it to determine the scope of its own holding:
The distinction between holding and dictum is an issue of technical legal doctrine. The Supreme Court is the ultimate arbiter of such issues in the US federal courts. If it were not, lower courts could disobey Supreme Court decisions they disagree with simply by declaring that they are dicta rather than holding. Moreover, the Supreme Court has issued many decisions expounding on what qualifies as dictum or holding. It would make little sense for them to do so if they did not have the power to define the difference.
Post is unconvinced. "If there’s a “mess” here, it’s a mess that Roberts created by saying “My discussion of the Commerce Clause is a holding of the Court” when it clearly isn’t one."