The Lord of the Rings: The Return of the King, Elijah Wood, 2003. | New Line/courtesy Everett CollectionThe Supreme Court’s Republican majority just did the legal equivalent of grabbing J.R.R. Tolkien’s One Ring, placing it on their collective fingers, and dancing around singing, “I just can’t wait to become a Nazgûl.”On Monday evening, the Court handed down Mirabelli v. Bonta, with all six of the Court’s Republicans in the majority, and all three Democrats in dissent (Republican Justices Clarence Thomas and Samuel Alito also signaled that they thought it was too moderate). Mirabelli is one of the most consequential constitutional decisions the Roberts Court has ever handed down.The immediate impact of Mirabelli is that California public school teachers must out transgender students to their parents, even if the students wish to keep their gender identity secret from their family. While the Court’s decision in Mirabelli is short and does not fully explain itself, the Republican majority appears to object to a California state law which provides that public school employees “shall not be required to disclose any information related to a pupil’s sexual orientation, gender identity, or gender expression to any other person without the pupil’s consent unless otherwise required by state or federal law.”Key takeawaysOn Monday night, the Supreme Court handed down a decision requiring public schools to out trans students to their parents.The Court grounded this decision in “substantive due process,” a legal theory that gives boundless power to judges, and that the Republican justices have historically opposed.Like J.R.R. Tolkien’s One Ring, the limitless power substantive due process offers to judges has tempted many generations of justices.The Court’s decision in Mirabelli is likely to impose impossible burdens on public schools.To reach this outcome, the Republican justices cite two provisions of the Constitution. The first is the First Amendment’s language protecting the “free exercise” of religion. The Republican justices claim that teachers who respect their trans students’ privacy “interfere with the ‘right of parents to guide the religious development of their children.’”This first part of the Court’s decision is likely to impose impossible obligations on public schools and their employees — are teachers now required to tell parents any time a student does something that their parents might object to on religious grounds, such as eating non-Kosher food, removing a hijab, or dating a classmate? But this first aspect of the Court’s decision in Mirabelli is at least consistent with the Republican justices’ prior cases interpreting the Free Exercise Clause.Last June, in Mahmoud v. Taylor (2025), the Republican justices ruled that public schools must inform parents in advance if they plan to teach books with LGBTQ characters or themes, and allow those parents to remove their child from those lessons. Since Justice Amy Coney Barrett’s 2020 confirmation gave Republicans a supermajority, the Court has been extraordinarily sympathetic to claims brought by the religious right.The second part of the Court’s Mirabelli decision is where the Republican justices grasp the One Ring. A legal doctrine called “substantive due process,” which judges can use to create constitutional rights not explicitly mentioned in the Constitution. In the early twentieth century, when economic conservatives were ascendant on the federal bench, the Supreme Court used substantive due process to invent a “right to contract” that the justices used to strike down workplace legislation such as minimum wage laws and laws protecting the right to unionize. In the 1960s and ’70s, when cultural liberalism was ascendant among legal elites, the justices invented a “right to privacy” that encompassed various sexual freedoms, including the right to an abortion.Modern-day Republican justices, largely due to their revulsion against Roe v. Wade, were previously vocal critics of substantive due process. Indeed, in her Mirabelli dissent, Justice Elena Kagan quotes several of her own Republican colleagues railing against this legal doctrine. Thomas, for example, wrote in 2015 that substantive due process is a “dangerous fiction” that allows judges to “‘roam at large in the constitutional field’ guided only by their personal views.” Similarly, Justice Neil Gorsuch warned in a 2018 opinion that “judicial misuse of the so-called ‘substantive component’ of due process” enables judges to “dictate policy on matters that belonged to the people to decide.”(For what it is worth, I agreed with Thomas and Gorsuch in a 2022 essay entitled “The uncomfortable problem with Roe v. Wade,” although I also argued in that piece that rights such as the right to abortion and to marry a person of the same sex, which the Court previously grounded in substantive due process, could instead be found within the Constitution’s guarantee that no one be denied the equal protection of the law.)But the widespread anti-trans panic among Republicans appears to have inspired all six of the GOP-appointed justices to abandon their past critiques of substantive due process and proudly wear the One Ring. The practical upshot is that the Court’s Republicans may now use this most dangerous of legal doctrines to strike down literally any law, or to otherwise impose their personal preferences on the nation.All that is happening now has happened beforeMirabelli is the height of judicial hypocrisy, but it’s hardly a surprise. It completes a cycle that has played out at least twice before in the last 150 years.The Constitution provides that no one shall be denied “life, liberty or property without due process of law.” Substantive due process is the idea that there are some “liberties” that are so important that no amount of legal process can justify restricting those liberties. Proponents of this controversial theory believe it is up to the Supreme Court to determine which “liberties” belong on this list of rights, and that these judicially created rights must be enforced even though they aren’t in the Constitution.In Lochner v. New York (1905), five justices used substantive due process to strike down a New York law providing that bakery workers could not work more than 60 hours in a week, and 10 hours in a day — at the time, these workers were typically paid on a daily or weekly basis, so working longer hours did not earn them more pay. Lochner claimed that the New York law “interferes with the right of contract between the employer and employees.” If a bakery worker agrees to an employment contract that calls for brutal hours and little pay, the five justices in the majority reasoned, lawmakers cannot interfere with that contract.The Court abandoned Lochner in West Coast Hotel v. Parrish (1937), which was decided shortly after President Franklin D. Roosevelt won his first reelection bid in a landslide. The combination of the Great Depression and the popularity of the New Deal turned the Court’s center against the laissez-faire approach to labor policy imagined by Lochner. And Roosevelt would go on to appoint eight justices to the Court, obliterating any remaining support for Lochnerism.Indeed, Justice Hugo Black, Roosevelt’s first appointment to the Supreme Court, said in 1967 that the reason “why I came on the Court” was because he “was against using due process to force the views of judges on the country.”For a few decades, Rooseveltian liberals dominated the Court, and these liberals — many of whom spent their early careers opposing substantive due process — kept the One Ring locked away. By the 1970s, however, the idea that the government should not interfere with people’s private sexual lives was so widespread among legal elites that even three of Republican President Richard Nixon’s four Supreme Court appointees joined the Court’s 7-2 decision in Roe. Roe situated the right to an abortion in “the Fourteenth Amendment’s concept of personal liberty and restrictions upon state action,” which was another way of saying “substantive due process.”Meanwhile, social conservatives disgusted by Roe and similar decisions took up the mantle of opposing substantive due process, often using the same rhetoric New Deal liberals once used to demand that the One Ring be cast into the fires of Mordor. Justice Antonin Scalia was the intellectual leader of this movement, writing in his Obergefell v. Hodges (2015) dissent that substantive due process “stands for nothing whatever, except those freedoms and entitlements that this Court really likes.”But President Donald Trump replaced Scalia with Gorsuch, a similarly conservative Republican whose behavior on the bench is much more erratic than Scalia’s. Then, Trump replaced Justice Anthony Kennedy, a moderate conservative, and Justice Ruth Bader Ginsburg, a feminist icon, with Justices Brett Kavanaugh and Amy Coney Barrett, both of whom are staunch social conservatives.And so, much as cultural liberals grasped the One Ring in the 1970s when their control over the Supreme Court was at its apex, social conservatives donned the same ring in Mirabelli. As plenty of legal scholars have previously noted, there appears to be a natural cycle that plays out every time a new political movement gains control of the Court. When that movement is out of power, it criticizes the incumbent justices for being too unrestrained, and for using substantive due process to achieve political ends. After that movement gains a majority on the Supreme Court, it often avoids the One Ring for many years or even for several decades. But the One Ring always tempts those who seek power. And justices inevitably reach for the Ring when they are most confident that they fully control the Court.The Ring cycle, in other words, appears inevitable. If a future Democratic president gets to replace Thomas and Alito, their appointees may resist the One Ring’s temptation for some time. But if Democrats hold onto the Supreme Court for long enough, they will succumb to its call.The Mirabelli decision is likely to prove unworkableNow that the Court’s Republicans have seized this forbidden power, the consequences for public education are likely to be dire.Mirabelli‘s immediate effect is to reinstate a trial judge’s decision holding that “when gender incongruence is observed…parents have a right to be informed” (a federal appeals court previously blocked that decision). But what on earth does it mean to “observe” gender incongruence? If a male student paints his nails, or if a female student wears a traditionally masculine article of clothing such as a necktie, must their teachers race to the phone to inform the student’s parents? Does “gender incongruence” include dating a member of the same sex? And, if so, what if a teacher observes ambiguous evidence that a student is gay, such as witnessing two female students holding hands? If a member of the drama club performs in a way that lampoons gender roles, does the Constitution force this student’s teacher to inform their parents?Now consider the Court’s first holding in Mirabelli, that parents have a religious right to be informed if their child’s gender identity conflicts with the parents’ religious beliefs. Does this holding apply to any other activity by a public school student that might conflict with their parents’ religious views? Are teachers required to inform on orthodox Jewish or Muslim students who eat bacon, in violation of their parents’ religious beliefs? If parents send a student to school wearing a headscarf, a kippah, or a cross necklace, do teachers have a constitutional obligation to inform the parents if the student takes it off? And, again, what happens if the student is gay? If a teacher learns that two male students are dating, do they have to immediately call the parents in case those parents object to homosexuality on religious grounds?Teaching algebra was hard enough before the Supreme Court ordered every public school teacher to become an enforcer of religious orthodoxy.As Justice Robert Jackson warned in a 1948 opinion, “authorities list 256 separate and substantial religious bodies to exist in the continental United States,” a number that has likely only grown as America became more diverse. If public schools must “eliminate everything that is objectionable to any of these warring sects or inconsistent with any of their doctrines, we will leave public education in shreds.”The best argument for judicial restraint has always been that the justices, who sit in their marble palace and know very little about running institutions like public schools, should avoid imposing their preferences because they risk sabotaging those institutions’ ability to function. After Mirabelli, I have nothing but pity for the poor public school teachers and administrators who now must balance the difficult task of earning the trust of their students with their new duties as religious informants.And now that the Republican justices have seized the One Ring, there is literally no limit to their ability to throw any American institution into chaos. Justice Thomas was right when he said that substantive due process empowers judges to “roam at large in the constitutional field guided only by their personal views.” He should have listened to himself.