As expected, the U.S. Supreme Court nationalized the right to bear arms in the recent case McDonald v. City of Chicago. They did this by “incorporating” the Second Amendment—that is, by requiring the states to abide by the restrictions in the Second Amendment that originally bound only the federal government.

Although gun-rights enthusiasts are understandably elated by this result, anyone who views original understanding in constitutional interpretation and modesty in the exercise of judicial power as quintessential judicial virtues must be deeply troubled. The Court’s plurality opinion, written by Justice Alito, eschews original understanding and reflects a lack of fidelity to text. The concurrence by Justice Thomas illustrates the peril of jurists misconstruing complex historical materials.

Building on the historically dubious conclusion that the Second Amendment (“a well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed”) contains an individual as opposed to a militia-related right to bear arms established in District of Columbia v. Heller (2008), the McDonald Court determined that the right discovered in Heller was sufficiently fundamental to be incorporated into the due-process clause of the fourteenth amendment and applied to the states. Now all gun regulations, whether enacted in the District of Columbia or by any state or municipal government, are subject to review by federal courts.

A textually unambiguous guarantee of procedural fairness, the due-process clause (“nor shall any state deprive any person of life, liberty, or property, without due process of law”) has of course been abused as a seemingly inexhaustible source of substantive rights invented by the Court over the years. It has also been the means by which the Court has taken certain protections in the Bill of Rights and applied them against state and local governments. Since 1897, the Court has engaged in “selective incorporation,” the piecemeal incorporation of protections found in the Bill of Rights. In McDonald, a plurality of the Court invoked this precedent to reach the result it wanted.

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The problem is that the jurisprudence of incorporation has no bearing on the due-process clause. As Justice Thomas pointed out, “All of this is a legal fiction. The notion that a constitutional provision that guarantees only ‘process’ before a person is deprived of life, liberty, or property could define the substance of those rights strains credulity for even the most casual user of words.” Yet Thomas agreed that the Heller reading of the second amendment should be incorporated. Rather than the plain dishonesty of using the due-process clause of the fourteenth amendment for that purpose, however, Thomas argued that the only sound textual course was to use the privileges-or-immunities clause of that same amendment (“No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States”).

The flaw with Thomas’s opinion is a real shortcoming in original-understanding interpretation. Working through dense historical materials—and the Fourteenth Amendment’s history is dense—is not something lawyers are trained to do. Thomas made a characteristically principled argument that incorporation was originally designed to take place through the privileges-and-immunities clause. The problem is that his history is all wrong. The most distinguished legal historian at work today is Philip Hamburger (author of the erudite books Separation of Church and State and Law and Judicial Duty), and his forthcoming article in the Northwestern University Law Review conclusively demonstrates that comity-clause rights for free blacks, not incorporation, was the original understanding of the clause. This point is not to argue against any historical inquiry—text and history are the only legitimate sources of constitutional meaning—but it is the reason why judicial modesty is utterly essential when law-office history brings about a revolution in our understanding of the regulation of guns.

There is no question that McDonald dramatically expands judicial power. This decision, in complete absence of textual or historical warrant to move into this area, will result in federal judges exercising what are fundamentally legislative judgments in all areas of gun policy. In his dissenting opinion, Justice Breyer provides a realistic sampling of the questions that will need to be addressed in future litigation:

Consider . . . that countless gun regulations of many shapes and sizes are in place in every State and in many local communities. Does the right to possess weapons for self-defense extend outside the home? To the car? To work? What sort of guns are necessary for self-defense? Handguns? Rifles? Semiautomatic weapons? When is a gun semi-automatic? Where are different kinds of weapons likely needed? Does time-of-day matter? Does the presence of a child in the house matter? Does the presence of a convicted felon in the house matter? Do police need special rules permitting patdowns designed to find guns? When do registration requirements become severe to the point that they amount to an unconstitutional ban? Who can possess guns and of what kind? Aliens? Prior drug offenders? Prior alcohol abusers? How would the right interact with a state or local government’s ability to take special measures during, say, national security emergencies?

Such is the steep price of judicial hubris.

Just as remarkably, McDonald provided no standard for reviewing the constitutionality of these questions. Once a standard is established, one can expect protracted and contentious litigation over all these sorts of questions. How the gun landscape will look in, say, ten years is anyone’s guess. While the Court asserted in Heller and repeated in McDonald that these decisions will not disturb long-established prohibitions on possession of firearms by felons and the mentally ill, bans on carrying guns into schools and government buildings, and the imposition of conditions and qualifications on the commercial sale of arms may be undermined or swept aside.

Because of McDonald, federal courts, not state and local elected officials, will now have the final word on the vast and complex area of social policy involving guns. Neither the text nor the history of the Constitution provides grounds for this radical shift in power. McDonald, alas, stands for the proposition that the excrescence of judicial legislation now has both a liberal and a conservative visage.