McDonald v. Chicago is the 2010 Supreme Court decision that extended the Second Amendment to state and local governments. By a 5-4 vote, the Court held that the individual right to keep and bear arms for self-defense, recognized two years earlier in District of Columbia v. Heller, is fundamental under the Fourteenth Amendment and binding on every level of government. The immediate result was the end of Chicago’s decades-old handgun ban and a rule that no city or state can prohibit handgun ownership in the home.
The Ban That Prompted the Case
In 1982, Chicago passed an ordinance requiring all firearms to be registered while refusing to accept any new handgun registrations. Residents who had registered a handgun before January 1982 could keep it. Everyone else was locked out. The suburb of Oak Park had a similar prohibition.
Otis McDonald, a 76-year-old retired maintenance engineer, lived in the Morgan Park neighborhood on Chicago’s South Side, an area he described as plagued by drug trafficking and gang violence. He had been burglarized five times, and his community activism against local drug dealers had made him a target for threats. He wanted a handgun at home for protection and could not legally have one. Three other Chicago residents joined his suit, and a parallel challenge by the National Rifle Association and two Oak Park residents was consolidated with it.
Why Heller Was Not Enough
Two years earlier, in District of Columbia v. Heller (2008), the Supreme Court had struck down a handgun ban in Washington, D.C., and held that the Second Amendment protects an individual right to possess firearms for self-defense in the home, separate from militia service. Because Washington, D.C., is a federal district, Heller only bound the federal government. The obvious follow-up question stayed open: could a state or city still ban handguns? McDonald was the vehicle to answer it.
Incorporation and the Fourteenth Amendment
The Bill of Rights originally restricted only the federal government. Most of its protections have since been applied to the states through a doctrine called incorporation, which runs through the Fourteenth Amendment. Free speech was incorporated long ago; other rights took decades. Before McDonald, the Court had never held that the Second Amendment applied to the states at all.
The petitioners offered two paths. Their primary argument relied on the Fourteenth Amendment’s Privileges or Immunities Clause, which forbids states from abridging the privileges or immunities of citizens. Their backup relied on the Due Process Clause, which forbids states from depriving anyone of liberty without due process of law. The Privileges or Immunities Clause had been largely dormant since the Slaughter-House Cases of 1873, which read it very narrowly.
What the Court Held
The Court ruled 5-4 that the Second Amendment right to keep and bear arms for self-defense applies fully to the states through the Fourteenth Amendment. The decision reversed the Seventh Circuit, which had upheld Chicago’s ban on the strength of nineteenth-century precedents predating modern incorporation doctrine. Justice Alito wrote the opinion, joined by Chief Justice Roberts and Justices Scalia and Kennedy. Justice Thomas supplied the fifth vote, concurring in the result on different reasoning.
Chicago’s handgun ban fell. So did Oak Park’s. No state or city could enforce the sort of blanket prohibition on handgun possession that Heller had already barred at the federal level.
The Majority’s Route
The majority incorporated the Second Amendment through the Due Process Clause and declined to revisit the Privileges or Immunities Clause. Under longstanding precedent, a right is incorporated through due process if it is “fundamental to our scheme of ordered liberty” or “deeply rooted in this Nation’s history and tradition.” The Court concluded the right to keep and bear arms met both tests, working through English common law, the founding era, and the Reconstruction period. The opinion placed particular weight on the framers of the Fourteenth Amendment, who were concerned about protecting newly freed Black citizens from Southern “Black Codes” designed to disarm them.
The majority also refused Chicago’s request to treat the Second Amendment as a second-class right subject to a weaker form of incorporation. Self-defense, the Court said, is not less important than the rights already fully applied to the states.
What Regulation Is Still Allowed
The Court was explicit that the right is “not unqualified.” Echoing Heller, the opinion listed regulations that remain permissible, including prohibitions on firearm possession by convicted felons and people with serious mental illness, bans on carrying weapons in sensitive places like schools and government buildings, and laws targeting straw purchases.
The Standard of Review Left Open
The majority did not specify what level of judicial scrutiny applies to firearm laws. Courts ordinarily use strict scrutiny, intermediate scrutiny, or rational basis review to evaluate laws that touch a constitutional right. McDonald left that question unanswered, as Heller had. Lower courts spent the next twelve years filling the gap on their own.
Justice Thomas’s Concurrence
Justice Thomas agreed the Chicago ban was unconstitutional but reached that result through the Privileges or Immunities Clause, not the Due Process Clause. He argued the Due Process Clause is the wrong tool because it speaks about process rather than the substance of rights, and that the Privileges or Immunities Clause was written to protect the fundamental rights of American citizens from state interference. He contended the Slaughter-House Cases misread the clause and should be reconsidered, and that the right to keep and bear arms was among the core privileges the Fourteenth Amendment’s framers meant to protect. No other justice joined this portion of his opinion.
The Dissents
Justice Stevens wrote that the majority asked the wrong question. Rather than incorporating the Second Amendment wholesale, he would have asked whether the Constitution guarantees a fundamental right to possess a handgun in the home enforceable against the states. He emphasized that states and cities face different patterns of gun violence and have distinct traditions around firearms, and that they should retain room to experiment. He also doubted judges have the technical capacity to assess gun-control measures.
Justice Breyer dissented separately, arguing the right to bear arms should not be treated as fundamental for private self-defense purposes. He drew a distinction between firearms and other rights: exercising the right to bear arms can put other people’s lives at risk in a way that speech or religious practice does not. He warned that the decision moved regulatory authority from elected legislatures to courts and questioned the majority’s historical analysis, noting that four justices had rejected Heller’s reading of history two years earlier.
What McDonald Changed
The immediate effect was the end of municipal handgun bans. Chicago replaced its ordinance with one that permitted handgun possession in the home but imposed registration requirements and banned gun sales inside city limits. Those replacement rules drew their own legal challenges.
The broader effect was structural. Every firearm regulation at every level of government now had to be measured against a constitutional right. Because the Court had not specified a standard of review, lower courts developed their own frameworks, most of them combining historical analysis with some form of means-end scrutiny that asked whether a regulation served an important government interest.
The Supreme Court resolved that split in New York State Rifle & Pistol Association v. Bruen (2022). Bruen rejected the two-step approach lower courts had used and held that when the Second Amendment’s text covers an individual’s conduct, the government must justify a regulation by showing it is “consistent with the Nation’s historical tradition of firearm regulation.” Bruen relied on McDonald’s observation that judges lack expertise in empirical cost-benefit judgments about firearms policy, and reaffirmed McDonald’s holding that individual self-defense is “the central component” of the Second Amendment right. Heller established the individual right, McDonald extended it to the states, and Bruen set the test courts now use to evaluate regulations that remain.