The 2017–18 Supreme Court term was noteworthy for many reasons. One is the fact that the Court overruled two longstanding (at least 40 years old) constitutional precedents by 5–4 votes, albeit with different lineups. In Janus v. American Federation of State, County and Municipal Employees, Council 31, the five more conservative justices held that it violates the First Amendment for public employees who choose not to become a member of the public sector union that represents them to nonetheless have to pay so-called “fair share” fees to the union to defray the cost of collective bargaining. In contrast, in South Dakota v. Wayfair, Justice Ginsburg joined four of the more conservative justices in the majority to uphold against a Commerce Clause challenge a state law requiring an online retailer that does significant business in the state but that lacks a brick-and-mortar presence in the state to collect and remit sales taxes, while the usually more conservative Chief Justice Roberts led Justices Breyer, Kagan and Sotomayor in dissent.

Notwithstanding these distinctive lineups (which perhaps can be explained at least in part by reference to the subject matter of the two cases) the justices’ writings in both cases, looked at in connection with each other, can help us better understand important principles about the proper way to implement the doctrine of horizontal stare decisis—the Court’s respect its own prior rulings. In particular, I focus below on the justices’ approach to three questions that are raised by one or both of the high-profile stare decisis cases of last term.

What’s So “Special” About Stare Decisis?

The first, and perhaps biggest, question is whether the Court needs some special reason, above and beyond a conviction that it made a mistake in a prior decision, to overrule itself. In the famous 1992 case of Planned Parenthood v. Casey, a majority of the Supreme Court explained why it was retaining the “essential holding” of Roe v. Wade notwithstanding substantial “reservations” that (at least some of) the justices in the majority had about the correctness of the Roe decision itself. The Court observed that while the rule of stare decisis is not an “inexorable command,” a decision to overrule an earlier case “should rest on some special reason over and above the belief that [the] prior case was wrongly decided.”

In other words, for the Casey majority, it was unclear that even a belief that an egregious error occurred in interpreting the Constitution in a prior case (here, Roe) would by itself constitute “special” justification for failing to follow precedent. (Of course I am not suggesting here that Roe does represent an egregious error, only that members of the Casey majority indicated that egregious error would not be enough to justify overturning past precedent.)

It is not entirely clear that a majority of justices still embrace that idea expressed in Casey. The majority in both the Janus and Wayfair cases did not use the word “special” at all in describing the permissible justifications for overturning past rulings. The closest either majority came was the admonition in Janus to the effect that “[w]e will not overturn a past decision unless there are strong grounds for doing so.”

But “strong” is an ambiguous term, and the Janus majority itself relied primarily on the wrongness of the decision it overruled (Abood v. Detroit Board of Education) as the basis for overruling.

As for the dissents in the two cases, while none of them quoted the language in Casey noted above, the two principal dissents (which together spoke for five of the nine justices) did use words that possibly connote the same idea. In Janus, Justice Kagan’s dissent for herself and three others, quoting from the 1984 Arizona v. Rumsey case, said: “Departures from stare decisis are supposed to be ‘exceptional action[s]’ demanding ‘special justification.’” And Chief Justice Roberts’s opinion for all the dissenters in Wayfair made similar noises (quoting from the same case): “Departing from the doctrine of stare decisis is an ‘exceptional action’ demanding ‘special justification.’”

But it is not clear that “exceptional” and “special” in these means something beyond the firm belief that the prior case was wrongly decided. (Recall that Casey didn’t simply say a “special” reason was needed; it said that what was required to justify overruling was a “special reason over and above the belief that [the] prior case was wrongly decided.” (emphasis added). “Special” as it is used in the Janus and Wayfair dissents, without the additional language from Casey, might mean simply a clear conviction of past mistake. (And since most of the time the Court thinks it got things right, fixing errors is something that is “special” or “exceptional” in the sense of being unusual.)

In any event, it would be wrong to require in all cases a special reason beyond a conviction of meaningful error in the past ruling. Understand that the Casey approach, taken seriously, would mean that so long as the older, wrong case identifies an easy-to-administer rule, no matter how bad the mistake was and how much harm it does to society, and even if there is no reliance on the mistaken ruling (as there often is not, say, in situations where the Court has wrongly upheld legislative power to victimize certain out-groups, as in the 1986 Bowers v. Hardwick case that was rightly overruled by Lawrence v. Texas in 2003), there should be no fixing it. This makes little sense. It is one thing to say we have to live with judicial mistakes because we value other things, like ease of administration and protecting reliance interests. (Oftentimes there are reliance interests to protect, as there were in Casey, which makes the conservatives’ disinclination to overrule in that case sensible even if the language I quote from the ruling is not.) But it is another to say we should live with mistakes as a matter of course, whether or not fixing the mistake would be unfair to those who have relied on it or would cause other collateral problems. Proponents of Casey’s approach have never explained why it makes sense to leave intact past mistakes as to which there has been no reliance. Perhaps someone could argue that a supercharged vision of stare decisis is grounded on a notion of judicial infallibility, but none of the justices appears to believe that prior volumes of the US Reports (the official reporter of the Court’s decisions) are free from interpretive error. Indeed, all the justices reject the notion of judicial infallibility, and argue strenuously that some past rulings (and the rulings in which they dissent today) are wrong. In this regard, it bears noting that some of the Supreme Court’s most celebrated (and legally correct) decisions (such as Brown v. Board of Education) involve overruling past cases that were wrongly decided.

Moreover, as my elder brother, Yale Law Professor Akhil Amar, and I argued many years ago when tackling this question, I think this “special justifications” approach wrongly submerges the meaning of the Constitution itself and improperly elevates the importance of the justices’ decisions. In other words, Casey’s reasoning privileges cases over the Constitution—the doctrine over the document. And yet the Constitution, not the Court’s case law, is what “We the People” ratified in the 1780s and later through the amendment process. It is the document that creates the judiciary, not vice versa.

Indeed, the same Constitution that establishes the federal courts and empowers them to hear cases “arising under this Constitution” requires all judges to swear an oath of allegiance not to their past rulings, but to the document itself. If neither the executive nor legislative branch of the federal government may unilaterally change the meaning of the Constitution, neither should the judiciary be able to do so.

In identifying precedents to support this view, we pointed first to John Marshall’s fountainhead 1803 opinion in Marbury v. Madison. That opinion makes clear that the entire basis of judicial review is to ensure compliance with the Constitution itself, as opposed to the misinterpretations of the Constitution by any branch of government—whether Congress or the President, or the judiciary itself.

Prior to Casey, the Court had never clearly articulated the “special justification above and beyond wrongness” approach; and in many important twentieth-century cases, the Court had in fact overruled its past precedents simply because it found them wrongly decided—exactly the approach Casey rejected. Casey itself cited to only two dissenting opinions (which carry no precedential weight) as authority to support its assertion of a need for a special reason beyond a belief of prior error. And the case that the Janus and Wayfair dissents both cite to support the notion that overruling past cases requires a “special” justification, Rumsey v. Arizona, in turn cites cases that directly undermine the Casey approach. Indeed, one of the cases Rumsey cites on how to apply stare decisis, Smith v. Allwright, observes that: “In reaching [the decision to overrule a prior case] we are not unmindful of the desirability of continuity of decision in constitutional questions. However, when convinced of former error, this Court has never felt constrained to follow precedent. In constitutional questions, where correction depends upon amendment and not upon legislative action this Court throughout its history has freely exercised its power to reexamine the basis of its constitutional decisions.”

None of this is to say that an earlier judicial decision by the Supreme Court should carry zero weight. By authorizing judicial review in cases “arising under this Constitution,” Article III of the Constitution itself contemplates that courts, particularly the Supreme Court, will craft doctrine to fill the gaps in the document. The Court will do so, the Constitution anticipates, by providing interpretations of the meaning of the Constitution, giving reasons for those interpretations, developing mediating principles, and crafting implementing frameworks to enable the document to function as in-court law.

Moreover, Article III envisions the Court as a continuous body, which never automatically turns over, the way the House turns over every two years and the presidency every four years. A continuous body would seem intentionally structured so as to give some weight to its past, and some thought to its future. It does not invent itself anew each day. Given this constitutional design—evident in the very structure of the document itself—I think it quite appropriate, indeed advisable, for the Court to give its past decisions a rebuttable presumption of correctness. A past case may properly control a present dispute until the past ruling is proved wrong, with those challenging it saddled with the burden of proving its wrongness.

And of course, Supreme Court precedents are binding on lower court judges, state and federal, regardless of whether these lower court judges are persuaded by the Court’s reasoning. The Constitution thus makes the high court “Supreme” not over the document itself, or over co-ordinate branches, but over judges of “inferior” courts. (More on that later.)

Constitutional vs. Statutory Stare Decisis

The Janus majority observed that the doctrine of stare decisis “is at its weakest when we interpret the Constitution because our interpretation can be altered only by constitutional amendment or by overruling our prior decisions.” And the dissent did not take issue with this.

In a similar vein, Chief Justice Roberts’s dissent in Wayfair argued that:

The bar [to overrule a past case] is even higher in fields in which Congress “exercises primary authority” and can, if it wishes, override this Court’s decisions with contrary legislation. In such cases, we have said that “the burden borne by the party advocating the abandonment of an established precedent” is “greater” than usual. That is so “even where the error is a matter of serious concern, provided correction can be had by legislation.”

And although the Wayfair majority disagreed with the dissenters about how easily Congress could overcome a wrongly created constitutional “default rule” in cases (of which Wayfair was one) involving the so-called Dormant Commerce Clause doctrine, the Wayfair majority did not quarrel with Chief Justice Roberts’s general idea that mistakes that Congress can’t fix are ones the Court needs to fix itself.

So the two big stare decisis cases from the past term show there is broad agreement on the Court for the commonsense idea that mistakes that Congress cannot remedy relatively easily are entitled to lesser precedential weight. But agreement on this principle simply reminds us that mistake correction is an important value—fixing mistakes is a factor on one side of the balance and something that, other things being equal, we should care about facilitating, But this acknowledgement itself undermines the Casey approach described above. If fixing mistakes is important, then why would we need a special justification beyond a strong belief an error was made in the prior case if the other side of the balance were zero (e.g., no reliance or other collateral damage done by overruling)? Again, perhaps reliance outweighs the need for error correction in particular cases, but, again, the Casey approach, taken seriously, would mean that even in the absence of reliance, something beyond a clear conviction of error is needed.

Reducing Reliance

As noted above, even if one rejects the Casey approach, the presence of reliance can, as in Casey itself, argue powerfully for following a past ruling even if some think that ruling was a mistake. Usually (though not always) there are some non-trivial reliance costs involved in overruling a past decision.

But can the Court do anything to blunt or minimize the reliance costs when it wants to correct a past mistake? In particular, can and should the Court telegraph that an overruling may be coming in the not-too-distant future so that people should and will rely less on the prior, mistaken ruling?

That is what the Court in Janus said it had been doing the last six years. Over that period of time, majority opinions from the Court had said that Abood (the case Janus overruled) was anomalous, and was based on extremely weak reasoning. And during this period but prior to its decision in Janus the Court had granted certiorari on the specific question whether to overrule Abood, and then (only because of Justice Scalia’s death) deadlocked 4–4 on that question. Based on these clear signals, the Janus majority said, reasonable reliance by public sector unions on the continuing vitality of Abood should have been reduced, and thus reliance interests posed less of a barrier to fixing what the Court thought was the Abood mistake.

In her dissent for herself and three others in Janus, Justice Kagan sharply disagreed. This argument, she said, “reflects a radically wrong understanding of how stare decisis operates.” She invoked a concurring opinion by Justice Scalia in a prior case where Scalia noted that the Supreme Court in Rodriguez de Quijas v. Shearson Lehman/American Express had admonished lower courts that “if a precedent of this Court has direct application in a case, yet appears to rest on reasons rejected in some other line of decisions, [they] should follow the case which directly controls, leaving to this Court the prerogative of overruling its own decisions.” That instruction, Justice Scalia explained, was “incompatible” with an expectation that “private parties anticipate [Court] overrulings.” Scalia concluded: “[R]eliance upon a square, unabandoned holding of the Supreme Court is always justifiable reliance.”

I think Justice Kagan’s invocation of Justice Scalia is unpersuasive, for many reasons. First, it is not a particularly meaningful use of precedent, since Scalia was writing for himself only. Second, it is not clear what Justice Scalia meant by “unabandoned.” Justice Scalia’s concurrence arguably differentiated between instances in which the Court went out of its way to say that notwithstanding possible doctrinal inconsistency the Court had no plans to overrule an outlying past case and indeed had repeatedly reaffirmed and distinguished it, and instances (like the pre-Janus half decade) in which the Court was in the process of “abandoning” a case (Abood) by criticizing it and making clear many members of the Court thought it was time to jettison it.

But whether or not Justice Kagan was properly channeling Justice Scalia, the invocation of the Rodriguez de Quijas teaching concerning the Court’s treatment of lower courts as being relevant to its treatment of reliance in the real world is wrong as a matter of precedent first principles. There are systemic reasons why we may want lower court judges to be formalistic rather than predictive in certain circumstances and not jump the gun to “underrule” past Supreme Court rulings that may no longer have majority support on the Court, but those reasons don’t apply to private persons outside the judiciary.

As my good friend Evan Caminker has pointed out, if some but not all lower courts decide that an old Supreme Court case is no longer worth following, then unless and until the Court validates that prediction there will be a lack of geographical uniformity in the meaning of federal law, which, while not itself unconstitutional, is hardly desirable (as the great Justice Joseph Story reminded us in the seminal Martin v. Hunter’s Lessee case two centuries ago.) In addition, “a bar on anticipatory overruling by lower courts would assuage any concerns that inferior courts might abuse [their power] by stretching to circumvent disfavored Supreme Court precedents based on relatively flimsy evidence that the Court might overrule them itself.”

But those concerns relating to geographic equality and discouraging disobedience within the administration of a federal judicial system have no bearing on the question whether private persons can and should reasonably read Court tea leaves. My own view is that we generally want the Court to be able to fix mistakes, and if reliance costs are an impediment to that we should look for ways the Court can legitimately reduce those costs, by sending clear messages that the outside world is encouraged to take seriously. An economist might argue that promoting private reliance on past, already decided rulings to the hilt is always a good thing—and maybe there is merit to this counterargument. But in any event, the way the Court wants lower courts to behave has nothing to say about how we want the private world to act. And that is why Justice Kagan needed to make an affirmative argument about the value of encouraging persistent reliance on the older precedent in the face of more recent criticism by the Court, rather than invoking an inapt concurring opinion by a single justice.