A.  The Decision

Bruen was a case nearly fifteen years in the making. In 2008, the Court decided District of Columbia v. Heller,¹⁵ the first Supreme Court case to hold that the Second Amendment guarantees a right to keep and bear arms for personal purposes like self-defense in the home. It was shortly followed by McDonald v. City of Chicago,¹⁶ which, by incorporating the Second Amendment through the Due Process Clause, vastly expanded the reach of the Second Amendment to cover every state and local jurisdiction in the nation. Although Heller and McDonald were undeniably watersheds in Second Amendment doctrine, they were Delphic in their guidance to lower courts.

Lower court judges scrambled to put together a doctrine that could implement this new right.¹⁷ They quickly converged on a two-step framework.¹⁸ At the first step, the lower courts used an approach—strongly influenced by history and Heller’s categorical distinctions¹⁹—to decide whether the Second Amendment covered the challenger’s activity. If it did not, then that was the end of the inquiry. Felons caught with firearms,²⁰ or challenges to guns in “sensitive places” like commercial airliners,²¹ usually failed at this step.

If the history was unclear, or the category underspecified, or the judge was cautious, courts would address step two, and apply a conventional means-end analysis calibrated by how close the regulation came to the “core” of the right. In doing so, courts would evaluate the stated government interest (typically described as public safety) and examine how closely the regulation fit with this stated goal compared to the expected burden on otherwise core Second Amendment conduct. Often, but not always, this analysis took the form of intermediate scrutiny. For example, the Third Circuit found firearms with obliterated serial numbers potentially within the coverage of the Second Amendment, because Heller did not categorically exclude them and because, unsurprisingly, there was no clear historical record of prohibiting ownership of unserialized firearms. Still, the prohibition survived, because preventing use of untraceable firearms in crime outweighs the minimal impact on a law-abiding person’s ability to use other weapons—in particular firearms with serial numbers—for the core purpose of self-defense in the home.²²

By the time the Court granted certiorari in Bruen, every federal circuit to directly address the issue had adopted this two-part framework.²³ But there were critics, including then-Judge Brett Kavanaugh of the U.S. Court of Appeals for the D.C. Circuit. In Heller v. District of Columbia (Heller II), Dick Heller—the successful plaintiff in the 2008 Supreme Court case—challenged the District of Columbia’s regulation of assault rifles and large capacity magazines as a violation of the Second Amendment.²⁴ The majority used the two-part framework and concluded that the District’s regulation was constitutional. In dissent, then-Judge Kavanaugh read Heller as forbidding any type of means-end scrutiny and argued instead that Second Amendment cases should be resolved solely by reference to “text, history, and tradition.”²⁵ A few other federal judges echoed his skepticism of the second part of the two-part framework,²⁶ and this methodological issue became a centerpiece of the briefing in Bruen.

Bruen dealt with a challenge to New York’s “may issue” permitting law. To obtain an unrestricted license to carry a handgun in New York, a person had to demonstrate “proper cause,” meaning some kind of need different than the self-defense interests of the general population. Two plaintiffs from upstate New York, Brandon Koch and Robert Nash, challenged the regulation as a violation of the Second Amendment. They were joined in the action by the National Rifle Association’s New York affiliate, the New York Rifle and Pistol Association, Inc. The tone of the Justices’ questions at oral argument made it apparent that New York’s regulation was going to fail; the only question was how broad the ruling would be, and on what grounds.²⁷ The options before the Court ranged from the factual and procedural—a remand for discovery about how licensing authorities were routinely using their discretion, for example—to the broad and disruptive—a complete revision of how Second Amendment cases should be decided.

The Court chose the latter course, overturning not only the Second Circuit’s ruling, but also a decade and a half of Second Amendment doctrine. Justice Thomas began his opinion for the Court by casting New York’s law as a departure from a national consensus: “In 43 States, the government issues licenses to carry based on objective criteria. But in six States, including New York, the government further conditions issuance of a license to carry on a citizen’s showing of some additional special need.”²⁸ The federal courts of appeals, with the exception of the D.C. Circuit, had routinely upheld these “proper cause” laws using the conventional two-part framework.²⁹ But the majority of courts were wrong, according to the majority in Bruen.

“Despite the popularity of [the] two-step approach, it is one step too many,”³⁰ wrote Justice Thomas. The first part of the test is “broadly consistent with Heller” because it is rooted in “text, as informed by history.”³¹ But the second part of the two-part framework was foreclosed by Heller, which “did not invoke any means-end test such as strict or intermediate scrutiny.”³² Means-end scrutiny is balancing, and balancing, according to the Court, is judge-empowering.³³ The proper balance of gun rights and regulation was set “by the traditions of the American people,”³⁴ and any contemporary assessment of costs and benefits is impermissible policy-making by the Third Branch.³⁵

Having rejected the circuits’ consensus approach, the Court announced a new test: “When the Second Amendment’s plain text covers an individual’s conduct, the Constitution presumptively protects that conduct. The government must then justify its regulation by demonstrating that it is consistent with the Nation’s historical tradition of firearm regulation.”³⁶ Under this new test, it isn’t enough for the government to simply “posit that the regulation promotes an important interest”;³⁷ it must “affirmatively prove that its firearm regulation is part of the historical tradition that delimits the outer bounds of the right to keep and bear arms.”³⁸

Of course, not every modern regulation has a historical duplicate. If it doesn’t, a court is to examine whether the modern regulation is “relevantly similar” to a historical one.³⁹ The Court declined to offer an “exhaustive survey” of what makes one regulation “relevantly similar” to another, but it did offer “two metrics: how and why the regulations burden a law-abiding citizen’s right to armed self-defense.”⁴⁰ The “central” considerations in this analogical process will be “whether modern and historical regulations impose a comparable burden on the right of armed self-defense and whether that burden is comparably justified.”⁴¹ The court emphasized that there need not be a historical “twin” to the modern regulation, but that any analogue must be “well-established and representative.”⁴² Upholding any remotely comparable historical regulation “‘risk[s] endorsing outliers that our ancestors would never have accepted.’”⁴³ This history-focused test, the Court reasoned, would rescue the Second Amendment from second-class status and restore it to equal dignity among the Bill of Rights.⁴⁴

Having articulated the new test, the Court applied it, concluding that the plain text of “bear arms” in the Second Amendment, according to original public understanding, means to carry weapons for self-defense.⁴⁵ The Second Amendment thus presumptively covered the plaintiffs’ conduct.

The burden then shifted to New York to show that its permitting law operated within a national tradition of regulation. New York and amici had amassed more than 700 years of Anglo-American regulation regarding public carry of firearms in an effort to show that New York’s law was no historical anomaly. Indeed, the New York law itself had been in place for more than a century, since at least 1911.⁴⁶ Nevertheless, the majority combed through all these regulations and explained away each one as an outlier with respect to a tradition of regulating public carry.

In doing so, the Court was bracingly candid: “not all history is created equal.”⁴⁷ It chopped the historical evidence into five categories: medieval to early modern England, colonial and early American Republic, antebellum, Reconstruction, and late nineteenth to early twentieth century. Having broken the historical evidence into pieces, the Court rejected it case by case, statute by statute.

The Court began with medieval and early-Modern English law. Although the Second Amendment reflects a “pre-existing” right inherited from our English ancestors, regulations that “long predate[]” the Second Amendment may not be indicative of a tradition “if linguistic or legal conventions changed in the intervening years.”⁴⁸ Therefore, the copious regulation of public arms from the thirteenth century to early modern England failed to establish a relevant tradition: they were too old, they had fallen into desuetude,⁴⁹ they were limited to armor and medieval weapons,⁵⁰ they were the product of partisan or sectarian hostility⁵¹ or domestic upheaval,⁵² or they required a mens rea of carrying weapons “to the terror of the people.”⁵³

Colonial regulations contemporary to 1791—the date of the Second Amendment’s ratification—did not fare any better. In the Court’s estimation, New York had produced only three regulations on public carry, and two of them were identical.⁵⁴ These regulations only proscribed “dangerous and unusual” weapons, and twenty- first century handguns are no longer “dangerous and unusual.”⁵⁵ The historical regulations only touched on concealed carry, and only of weapons with three to four inch barrel lengths;⁵⁶ they didn’t prohibit the carrying of long guns.⁵⁷ They also required a mens rea of “causing terror.”⁵⁸

Although New York had produced substantial evidence of common law and statutory regulation of public carry, this too was insufficient to form a tradition supporting New York’s law. The Court found that the antebellum cases all required a showing of terror, and there was “no evidence indicating that these common-law limitations impaired the right of the general population to peaceable public carry.”⁵⁹ Further, some regulations permitted open carry.⁶⁰ All were too new, as they were enacted seven decades after ratification of the Second Amendment.⁶¹ Some were enacted by territorial jurisdictions that were not yet states.⁶² The ten jurisdictions which passed surety statutes—statutes that required a bond to carry weapons in public—only addressed persons “threatening to do harm”⁶³ and required a citizen complaint (except for two antebellum laws in Virginia and West Virginia, which were, according to the Court, outliers⁶⁴). Further, these surety laws were not clearly shown to be enforced, or were enforced pretextually, or were enforced with insufficient criminal sanction.⁶⁵ All of this made them “poor analogues to New York’s proper-cause standard.”⁶⁶

Reconstruction regulations also failed to establish a tradition. A general order by a Union commander in the Carolinas to prevent the carrying of deadly weapons, except by those in active military service, was a wartime exigency subject to military jurisdiction, and therefore inapt.⁶⁷ Some regulations were applied in a racially partial manner, and (presumably) suspect for that reason.⁶⁸ The Court “acknowledge[d]” that two late 1800s Texas cases and a West Virginia Supreme Court case all upheld statutes requiring “reasonable grounds” to carry weapons, which were analogous to “New York’s proper-cause requirement,” but these were dismissed as outliers because they were only a “single state statute and a pair of state-court decisions.”⁶⁹

Late nineteenth-century regulations, like prohibitions on firearms in towns, cities and villages, suffered from several defects. First, they were too remote from the Founding; second, “the vast majority” of the evidence “came from the Western Territories,”⁷⁰ even then, the regulations were too “localized,” and governed “less than 1% of the American population” at the time.⁷¹ Further, the regulations were not often litigated, obscuring their “perceived legality”; they excepted certain types of weapons, and those that were upheld conflicted with the decision one hundred years later in Heller.⁷² These territorial restrictions were thus “passing regulatory efforts by not-yet-mature jurisdictions on the way to statehood, rather than part of an enduring American tradition of state regulation.”⁷³ One state regulation potentially analogous to New York’s was a 1881 Kansas statute obliging cities with more than 15,000 residents to regulate arms. But, according to the Court, that only covered Kansas City, Topeka, and Wichita, which “[a]ccounted for only 6.5% of Kansas’s total population.”⁷⁴

In sum, according to the Court, the seven hundred years of history that New York and amici had produced could not demonstrate a long American tradition of regulating arms with a “proper cause” standard—at least not once the outliers were removed. Hence, the law violated the Second Amendment.

B.  Analysis and Open Questions

Whatever one’s view of New York’s regulation, Bruen’s new methodology represents a problematic shift in Second Amendment doctrine, and perhaps constitutional law more generally. Just how big of a problem remains unclear, as it is not apparent how broadly Bruen sweeps. Three Justices in the majority wrote or joined concurrences that appear to trim the ambition of Justice Thomas’s opinion—either as to the topics it covers or the methods it employs or both.

Justice Samuel Alito suggested that the historical analysis only goes to the unconstitutionality of a permitting law like New York’s: “That is all we decide.”⁷⁵ According to Alito, the ruling says nothing about who may buy firearms, or what they must do to buy them; it doesn’t decide anything about the kinds of arms that are constitutionally protected, “[n]or have we disturbed anything that we said in [Heller or McDonald] about restrictions that may be imposed on the possession or carrying of guns.”⁷⁶

Justice Brett Kavanaugh, joined by Chief Justice John Roberts, wrote a separate concurrence that also seemed to cool Bruen’s revolutionary fire. On his account, there are “limits” to the Court’s opinion. The decision “does not prohibit States from imposing licensing requirements for carrying a handgun in self-defense” along the lines of the forty-three other states with “shall-issue” laws that use more objective metrics. Further, “[p]roperly interpreted, the Second Amendment allows a ‘variety’ of gun regulations.”⁷⁷ To emphasize the point, Justice Kavanaugh reproduced assurances from Heller and McDonald that the Court was not scrapping all gun regulations. “Like most rights, the right secured by the Second Amendment is not unlimited,” he reiterated:

Then there’s the uncertainty within the Bruen framework itself. Justice Thomas stated that so long as an individual’s conduct falls within the “plain text” of the Second Amendment, it is presumptively protected and the burden shifts to the party defending the regulation to show that it is part of a longstanding American tradition. But that’s almost certainly not right. A seventeen year old bringing a live hand grenade into a high school cafeteria fits within the plain text of “people” and “arms” and “bear.”⁸⁰ It cannot be that such behavior raises a prima facie Second Amendment issue such that the school district must prove a longstanding tradition of keeping minor children from bringing explosives to school. Indeed, the majority itself suggests elsewhere that the first step is not just “plain text” but “text, as informed by history.”⁸¹ If that’s the case, then it appears incumbent upon the challenger of a regulation to show more than that his conduct falls within the dictionary meaning of the Second Amendment’s words; he must show how his conduct falls within a textually specified historical practice that was widely understood to be a matter of right. Only then would the burden shift to the defenders to establish a tradition of regulation.

Perhaps most perplexing, Bruen relied heavily on analogy but never specified criteria for determining when a present-day regulation is relevantly, as opposed to trivially, analogous to one in the past.⁸² The majority assures us that its demand for analogues is neither a “regulatory straightjacket” nor a “blank check,” but provides slender guidance on how to pilot between these two hazards. Instead, we get a set of abstractions: an analogue must be “well established and representative” instead of an “outlier.”⁸³ For a “general societal problem that has persisted since the 18th century,” the analogue must operate in “materially” similar ways and not have been “rejected on constitutional grounds” by some undetermined number of jurisdictions, or else it’s a historical anomaly that cannot support the contemporary regulation.⁸⁴

So how is a court supposed to analyze firearms on subways or airplanes? How should one describe the general societal problem in that context, and with what evidence? Is it gun violence generally? Is it terrorism? What does a “representative historical analogue” look like before the advent of railroads and airplanes? A boat? A buggy?⁸⁵ Are regulations forbidding the firing of guns from the decks of riverboats⁸⁶ “materially different” from regulations forbidding the possession of loaded guns in carry-on luggage? Or should the analogue be weapon regulation in areas of intense congestion, like fairs and markets? The Court says that judges are to look to “how and why” the analogous regulation burdens a right to armed self-defense, but that, as Justice Breyer notes in dissent, is exactly what means-end scrutiny is supposed to do.⁸⁷

Working with analogues may be possible when there’s a historical equivalent. But how courts will find, much less assess, “representative historical analogue[s]” to modern prohibitions on guns on subway cars and jet airplanes, or possession of untraceable firearms,⁸⁸ or possession by domestic abusers, remains distressingly indefinite.⁸⁹

A.  Transparency

A central defect of Bruen is the suggestion that its “outliers” were simply found. They weren’t. They were created. Bruen’s outliers are the product of decisions both inside and outside the Court, motivated by express and assumed judgments about how to count, and what counts. But the Court does not explain, much less justify, how it is constructing its baseline or how evidence deviates meaningfully from that baseline. The result is an impressionistic and seemingly arbitrary set of conclusions that at best mask the values animating the analysis, and at worse appear to be post-hoc reasoning for a pre-determined outcome.

There are, in fact, varying accounts of why the Supreme Court might nationalize legal standards against outliers.⁹⁰ The Court might trim outliers because state laws are a rough proxy for political consensus.⁹¹ The Court might trim outliers because it’s attempting to ascertain the original public understanding of a constitutional provision. Or the Court might trim outliers because it becomes satisfied from sub-constitutional consensus that nationalization will be net positive and will not generate catastrophic outcomes.⁹²

Whatever the reason, identifying outliers requires choosing a reference set, and that choice is freighted with value judgments.⁹³ For example, using the States as the unit of measure for political consensus assumes the states are a superior proxy for the political preferences of their residents than other proxies. Discerning original public meaning from litigated cases assumes litigated cases are a reliable metric for public understanding. All these assumptions are unstated, and all do a lot of work in Bruen’s definition of outliers.

Take the Court’s insistence that New York’s “may issue” law was anomalous compared to that of forty-three other states. The first, unstated assumption is that states are the right reference set, even if some of these states are thinly populated or lack urban centers. If the Court had used population as the relevant denominator, then New York’s law is not an outlier—good cause permitting covers fully a quarter of the American population, including some of the highest population densities in the country.⁹⁴ In fact, elsewhere in the opinion the Court does invoke population as a relevant metric, dismissing various gun laws in the territories as outliers because of “the miniscule territorial populations who would have lived under them.”⁹⁵ It is not clear from the opinion why population is relevant in one context but not the other.

If at-large population is the wrong denominator, why should states be the right one? New York’s law would have looked far more typical if the denominator had been large municipal governments.⁹⁶ If you combine the populations of Maine, Rhode Island, Montana, Delaware, South Dakota, North Dakota, Alaska, Vermont, and Wyoming it still doesn’t equal the population of the City of New York. And even that approach might under-represent political preferences, considering that nearly all the forty-three states with “shall issue” or permitless carry also preempt local governments from enacting their own gun regulations.⁹⁷ That means that major urban centers like Houston and Phoenix may have their preferences unaccounted for when the unit of measure is legal regulation, because they’re prohibited from registering their preferences as law. Further, some of this legislation (or absence of it) is the product of either a heavily gerrymandered state legislative map⁹⁸ or an equally skewed direct democracy mechanism.⁹⁹ The result is a data set that provides more voice to rural and less diverse populations compared to urban and multi-racial populations.

Finally, as Justice Breyer remarked in dissent, New York is only an outlier given a “snapshot” of the law in 2022.¹⁰⁰ Look back just forty years and the ratio is completely reversed: “shall issue” was limited to just five states¹⁰¹ and permitless carry was the law of just one.¹⁰² New York went from being fairly representative to an outlier thanks to lobbying by gun-rights advocates, legislation by pro-gun state assemblies, and naked appeals to popular notions of the Constitution, history, and tradition.¹⁰³

As Professor Jake Charles has documented, as recently as 1980 fully one-quarter of states outlawed concealed carry altogether, with most of the other states operating a “proper cause” or similar “may issue” licensing regime.¹⁰⁴ But “[t]his paradigm began to erode dramatically in the 1980s.”¹⁰⁵ Florida kicked off a wave of state law changes when it adopted a “shall issue” law that retained certain requirements, but removed the “special need” or “proper cause” element.¹⁰⁶ By the time Bruen was decided, there was not a single jurisdiction in the United States that did not allow some form of concealed carry.¹⁰⁷

A second wave of gun-rights legislation began to build shortly before the Heller decision in 2008, and soon overtook established institutions of gun-rights advocacy like the NRA. The permitless or “constitutional carry” movement was initiated in an Arizona diner around 2005,¹⁰⁸ and by 2020 had spread to sixteen states. With the repeal of permitting in Alabama and Florida in 2023, over half of the states are now permitless.

These legislative innovations often speak in a specific constitutional register, as the “constitutional carry” terminology attests. Washington’s permitting law, for instance, has a preface that “[t]he applicant’s constitutional right to bear arms shall not be denied, unless …”¹⁰⁹ The Governor of Georgia, signing a permitless carry act in 2022 announced, “The Constitution of the United States gives us that right [to carry without a permit] – not the government.”¹¹⁰ For proponents of “constitutional carry” in particular, the idea that the only permit necessary to carry a firearm was signed in 1791 is not a slogan, it’s a legal and historical reality. Although the historical record supporting a tradition of permitless concealed carry is thin to non-existent—Heller itself recognized as much¹¹¹—that does not stop adherents from arguing that American tradition and constitutional law is on their side. The majority leader of the New Hampshire Senate, for example, explained his support this way: “We have historically allowed people to openly carry a pistol. I don’t see why you have to get a second permit if you’re a law-abiding citizen and legally entitled to own a gun.”¹¹² A sponsor of a permitless carry bill in Utah said: “I have that right to protect myself, the Constitution says we have the right. Why are we putting a barrier for law-abiding citizens?”¹¹³ The sponsor of the Ohio permitless carry bill made similar remarks: “Responsible gun owners should not be punished for lawfully practicing their constitutional rights.”¹¹⁴ The attitude can be summarized by one journalist who interviewed “constitutional carry” advocates: “The concept, rooted in constitutional originalism, assumes that the authors of the Second Amendment envisioned an unfettered right to wield a gun for personal defense.”¹¹⁵ To these adherents, “any limitation on an individual’s right to carry guns, however small, is unjust. Full stop. As such, passing constitutional-carry legislation is seen by proponents as a restoration, not an expansion, of gun freedoms.”¹¹⁶ The normativity of those arguments is evident—though unrecognized—in the Court’s own treatment of the historical record.

Bruen says the historical laws supporting New York’s regulation are outliers compared to the tradition of public carry regulation. But Bruen creates that tradition through a series of choices about the level of generality at which to identify a practice, the level of generality at which to identify a regulation, and the relevant denominator of practices, laws, groups and political units at which to define the tradition.¹¹⁷

Consider how Bruen dismisses the stringent regulations on public carry in the Western territories. Justice Thomas describes these regulations as outliers because they did not survive the transition into statehood.¹¹⁸ That might be defensible if states were good proxies for consensus on the original understanding of the Second Amendment. But it is indefensible if the best measure of original understanding are those jurisdictions subject to the Second Amendment before the advent of incorporation. In those circumstances, the most probative reference set would be the territories, because they—unlike states—were subject to the Bill of Rights. In that sense, as Andrew Willinger notes, “the five territorial public-carry laws the Court declined to credit in Bruen may not be outliers at all, but in fact may hold crucial clues to the meaning of the federal Second Amendment in the 19th century.”¹¹⁹

Similarly, the Court treats historical laws banning the carrying of concealable weapons as outliers when compared to four states that struck down similar regulations in the South.¹²⁰ But why are litigated cases the relevant metric for accurately assessing the legal tradition? Why wouldn’t the relevant metric include all those jurisdictions where regulations went unchallenged (or unenacted) because the practice was socially frowned upon—and therefore rare¹²¹—or unchallenged because no one thought the Second Amendment had anything to say about the regulation?¹²² In fact, the Court takes precisely this kind of approach when reiterating the constitutionality of restrictions on guns in “sensitive places” like polling places and courthouses, saying “we are also aware of no disputes regarding the lawfulness of such prohibitions. We therefore can assume it settled that these locations were ‘sensitive places’ where arms carrying could be prohibited consistent with the Second Amendment.”¹²³ If the relevant metric for tradition is not “what was litigated” but “what did people do and believe” then all kinds of historical sources, including newspaper articles, opinion pieces, letters and other materials should be evidence of the relevant “tradition,”¹²⁴ not just litigated cases available on Westlaw.

The difficulty here goes beyond the challenge of excavating historical sources, dealing with historical silences, and managing the disjunction between the craft of historians and that of judges. The Court has failed to acknowledge the inevitable role of “creativity and interpretive choice” that shapes its treatment of the historical record.¹²⁵ By dismissing so much of the historical evidence, and then regarding the remainder as a self-evident, pre-existing, and neutral baseline, the Court confuses an exercise in discretion for a process of discovery.

B.  Rigor

If Bruen’s first shortcoming is a lack of candor about its own role in manufacturing outliers, its second shortcoming is a lack of rigor in defining them.¹²⁶ Calling something an outlier suggests the categorization is based on some kind of empiricism, something objective, falsifiable and roughly quantitative, based on a method that submits to a disciplinary standard. This is consistent with the general claim that originalism, in particular, can supply a kind of empirical determinacy with history and tradition that other methods of constitutional interpretation cannot.¹²⁷ An “I know it when I see it” standard for outliers is unsuitable to a claim that purports to an empirical statement of fact.

Where might one begin to articulate the minimum rigor for outlier analysis in constitutional law?¹²⁸ Given that the term itself seems borrowed from empirically-oriented disciplines—and is being used to similar ends—one might take some guidance from outside the law. The National Institute of Standards and Technologies defines outlier this way:

Three implications flow from this definition. First, there needs to be a sufficient sample to determine whether there’s a distribution. A single point can’t be an outlier. Second, the sample has to fall within an identifiable grouping—there are no outliers when every point is an outlier. And, although researchers exercise some discretion in designating a data point as “abnormal” relative to the distribution, the discretion is not unbounded. There may be a “consensus process” to determine whether to recognize the data point as an outlier; there may be norms of the profession to justify whether something lies outside the distribution. Finally, outliers must be the result of observations. At the very least, an outlier designation can be challenged by other researchers based on a set of pre-existing criteria. Moreover, in any empirical project it’s highly unorthodox—and usually forbidden—to cherry pick the data to fit a distribution you seek, rather than have the data determine the distribution.

Observations also have to be grouped according to some set of criteria or coding.¹³⁰ The norms of empirical disciplines vary, but the process tends to be designed to generate reliable data that minimizes bias or error,¹³¹ is transparent and, if possible, is replicable.¹³² Second, the more potential for bias to creep into the exercise, the more it needs to be distanced from the researcher.¹³³ In some empirical disciplines, for example, it’s preferable to have blind coding—where the coders are given a set of parameters, but not given any information about the theory for which they are coding.¹³⁴ In other disciplines, the coding is done by two different individuals, with a third resolving disputes between the codes based on a set of ex-ante metrics.¹³⁵

Describing the outlier analysis as a search for “tradition” does not eliminate the need for rigor.¹³⁶ Invocation of a “tradition” also presumes some kind of empiricism. Sociologists define tradition as “[a] set of social practices which seek to celebrate and inculcate certain behavioural norms and values, implying continuity with a real or imagined past, and usually associated with widely accepted rituals or other forms of symbolic behaviour.”¹³⁷ Although the data sets and coding may be different than more quantitative projects, identifying a “tradition” still requires designation of a relevant community and some set of phenomena, practices, or regulations sufficient in number and similarity to form a distribution, and some duration of time.¹³⁸ Practices that deviate meaningfully from this grouping are outliers.

This is an incomplete survey, and we do not think that courts must necessarily adopt the definitions and norms of these disciplines.¹³⁹ But the alternative for law cannot be the kind of erratic, impressionistic approach on display in Bruen. Empirical standards exist among these other disciplines and share common features, and law should expect empirical conclusions about outliers to rely on processes of comparable rigor.¹⁴⁰

Indeed, law already aspires to this kind of rigor in many different ways, employing techniques that effectively treat claims about outliers as matters of empirical fact. The content of customary international law, for instance, has long been defined as “a general and consistent practice of states followed by them from a sense of legal obligation.”¹⁴¹ At least one component of this doctrine looks to a generalizable practice among nations,¹⁴² followed over some duration of time—a determination that is supposed to be an empirical exercise.¹⁴³ Tort law routinely pegs a duty of care for professional service providers—like physicians—to a standard of care common to comparable experts.¹⁴⁴ And there are theories of the “reasonable person” that depend on observed behavior of a representative sample of people, rather than on a normative fiction of what a person should do.¹⁴⁵ Outside the Second Amendment, in other areas of constitutional law, judgments rest on empirical assertions of what is “cruel and unusual punishment,”¹⁴⁶ or what offends “contemporary community standards.”¹⁴⁷

Although the sophistication of empirical analysis varies across these domains, we would expect that, to the extent any of them make factual assertions about the world, they would engage in a methodologically rigorous process that produces, within some set of professionally agreed-upon parameters, an empirically falsifiable project. Like the more-transparently empirical disciplines discussed above, they begin with an identifiable grouping of sufficient size (nations, professionals, states) compare them according to the variable of interest (practice, standard of care, punishments), using standards not selected by the legal decisionmaker itself.

Bruen does none of this.¹⁴⁸ At least, it doesn’t do so in any way that’s obvious or conforms to the best practices common to empirical work. None of the quality control techniques one would expect of other disciplines appear to have been employed in Bruen. To the extent that customs, traditions, and baselines have been established at all, they seem to have been done through amicus briefing on appeal—not, for example, through dispassionate accumulation and characterization of the evidence, or for that matter even through adversarial testing of claims (whether historical or otherwise) at trial.

To the contrary, the Court makes confident generalizations based on phenomenon that might themselves be outliers. The two petitioners were denied licenses, but their Second Amendment challenge was decided on the pleadings, meaning that there is no record evidence to support the majority’s conclusions that there is “limited” judicial review of license denials, that New York’s law is too “demanding” and that this makes New York an outlier compared to the “vast majority of states.”¹⁴⁹ It is entirely possible that the petitioners’ experience was completely unrepresentative.

Further, the Court treats historical cases that are arguably outliers as indicative of broad historical trends. For example, the majority calls Nunn v. State “particularly instructive.”¹⁵⁰ In that case, the Georgia Supreme Court applied the Second Amendment to state law at a time when Georgia had no similar provision in its state constitution, and just over a decade after the Court held that the Bill of Rights was not applicable to the states.¹⁵¹ By nearly any measure, Nunn’s understanding of the Second Amendment was an outlier in antebellum America. And yet the majority reads it to “indicate[] that it was considered beyond the constitutional pale in antebellum America to altogether prohibit public carry.”¹⁵² If a single state case can stand for the scope of a constitutional right “in antebellum America” then how can the Court dismiss, for example, Texas’s Reconstruction-era regulations as outliers? Or, for that matter, why should Nunn count so much more than the “handful” of jurisdictions with laws that, even under the Court’s own telling, supported New York?¹⁵³

Consider, too, Justice Alito’s assertion that the two-part doctrinal framework adopted throughout the federal courts of appeal “places no firm limits on the ability of judges to sustain any law restricting the possession or use of a gun. Two examples illustrate the point.”¹⁵⁴ Considering that more than 1,000 Second Amendment challenges were resolved in the eight years after Heller—and probably more than 1,500 by the time Bruen was decided—one might expect more than two examples to sustain such a broad generalization, much less justify the doctrinal chaos Bruen threatens to unleash.

C.  Manufacturing Outliers and the Integrity of Historical Reasoning

The risk of non-transparent and improvised outlier analysis is not simply that it may result in unjustifiable or erratic case outcomes. It threatens the integrity of history as a modality of constitutional interpretation.¹⁵⁵ A chief selling point of originalism has always been that history is an objective and falsifiable metric that can constrain judicial decision-making. But you need not buy all the judicial-constraint optimism of Ed Meese-era originalism to believe that statements of historical fact pronounced by the Court and statement of historical fact rendered by professional historians need share the same epistemic universe. A Court that repeatedly elevates one set of historical premises and denigrates the other, and then suffocates contrary historical evidence as “irrelevant” based solely upon its prior decrees about history, risks an ever-increasing separation of law-office history from actual history.¹⁵⁶

For example, in Heller, the Court was faced with a record containing many historical examples of strict and even prohibitionist gun regulation. Some courts applying Heller treated these historical laws as tainted, since some of them were based on the traditional view—rejected in Heller—that the right to keep and bear arms extended only to the organized militia.¹⁵⁷ Bruen engages in this same foreshortened historical investigation as well, discounting nineteenth century historical evidence when it is inconsistent with what Heller said over a century later.¹⁵⁸

Every time the Court cuts off one of these lines of tradition as incompatible with its own historical construction, it shifts the baseline and the center of gravity for judicial history drifts further from the corpus of actual history.¹⁵⁹ Iterative pronouncements based on manufactured outliers are likely to continue in this context and in others, as the Court treats its holdings as precedential not only as to matters of law, but also matters of historical fact.¹⁶⁰

This ratcheting effect may lead constitutional law further and further from both a historical baseline and contemporary best practices. As described above, “may issue” is an outlier as a result of a careful program of legislation and cultivation of constitutional memory.¹⁶¹ But once you lop off “may issue,” then “shall issue” becomes exposed. Employing the very same mechanisms that led to Bruen could lead another court to describe “shall issue” as the outlier and argue that permitless carry is what’s required by the history and tradition of the Second Amendment. Nor is that kind of ratcheting confined to the issue of public carry. We can see the appeal of this tool to gun rights supporters who want to target other regulations—whether those are prohibitions on large capacity magazines and “M-16 rifles and the like,”¹⁶² age restrictions on who may possess firearms; extreme risk protection orders; training requirements to carry; and so forth. All you have to do is pull the legislative levers with receptive legislatures, support the position with a particular form of constitutional memory, present the target jurisdiction as a contemporary and historical outlier, and what had—to invert Jack Balkin’s framework—formerly been “on the wall” is rendered “off the wall.”¹⁶³ The result may be an American firearm policy that ironically becomes less and less the work of legislatures and representative branches of government and more and more the exclusive task of judicial officers using crude adjudicative tools and an invented historical tradition.¹⁶⁴