Judge Kavanaugh will almost certainly be grilled at his confirmation hearing about his view of precedent (stare decisis in the Latin phrase that lawyers often use). Opponents will see this as having direct implications for Roe v. Wade and abortion, and for many other constitutional issues as well.

Opponents won’t find much in Kavanaugh’s twelve years on the D.C. Circuit, because lower federal court judges lack authority to overturn Supreme Court decisions. In the American constitutional system, the federal courts are organized in a hierarchical system, and lower courts are inferior to the Supreme Court and hence cannot refuse to follow its precedent. Only the Supreme Court can reconsider one of its own precedents, because lower federal courts are obliged to scrupulously follow Supreme Court decisions “which directly control[],” as the Court said in a 1997 decision, Agostini v. Felton.

And Judge Kavanaugh has taken that obligation of lower court judges seriously. In his 2015 opinion in Priests for Life v. HHS, addressing the HHS mandate, Kavanaugh emphasized that the D.C. Circuit was bound by the Supreme Court’s decision inHobby Lobby:

We are a lower court in a hierarchical judicial system headed by “one supreme Court” [citing the US Constitution, Art. III, sec. 1]. It is not our job to re-litigate or trim or expand Supreme Court decisions.  Our job is to follow them as closely and carefully and dispassionately as we can.

Even if they wanted to, there are no practical means for a lower federal appeals court judge to effectively overturn a Supreme Court precedent. He or she would need a second judge to form a two-judge majority on the three-judge panels that decide most appellate court cases, and their decision would be appealable to the Supreme Court. The most that they can do practically is to criticize Supreme Court decisions, hoping that they might influence the Justices (as Judge Edith Jones of the Fifth Circuit criticized Roe in McCorvey v. Hill in 2004).)

Nor will they find much in Judge Kavanaugh’s extra-judicial writings. Judge Kavanaugh is one of 13 co-authors of a 2016 book on The Law of Judicial Precedent. Whatever Kavanaugh or any other co-author contributed to the book is unknown—the co-author contributions are anonymous, they are simply listed as “co-authors.”  (In the words of the marketing release, “without signed sections, but instead writing with a single voice.”) https://legalsolutions.thomsonreuters.com/law-products/c/The-Law-of-Judicial-Precedent/p/103914241.

However, the question of what lawyers call “vertical precedent” (a lower court’s duty to follow Supreme Court decisions) is significantly different from “horizontal precedent” (the Supreme Court’s duty to follow its own decisions). This will be a new capacity for Judge Kavanaugh if confirmed, as it is for every Supreme Court Justice.

Generally, over the past few decades, Supreme Court justices have looked at six factors—from time to time and with varying consistency—in reexamining precedent: whether the prior decision is settled, whether it was wrongly decided, whether the standard it sets out is workable, whether factual changes have eroded the prior decision, whether legal changes have eroded the prior decision, and whether reliance interests in the prior decision are substantial.  The Justices looked at many if not all of these factors in two decisions at the end of the last (2017) Term, in South Dakota v. Wayfair and Janus v. AFSCME.  In practice, these factors have considerable wiggle room.

These six factors could be reduced to three questions: did the Court err in the original decision, was the error substantial, and what is the cost of fixing the error?

Scholars refer to a “strong” and a “weak” view of precedent.  Will Judge Kavanaugh have a strong view or a weak view of precedent, or something in between?  He may put particular emphasis on the “wrongly decided” factor, as Justice Scalia and Thomas have, or he may take the view of Chief Justice Roberts that the “wrongly decided” factor cannot be decisive and that “special justification” is required to overturn precedent.  It is likely Judge Kavanaugh will touch on these factors at his confirmation hearing, without taking a specific position.