So what did the Court say in its first elaboration on the clause since the 1939 Miller decision? Justice Scalia penned the majority opinion in Heller, and its key conclusions are as follows. First, that the Second Amendment was historically understood to include the right to bear arms for immediate self-defense in the home, and that right includes handguns:
It is no answer to say, as petitioners do, that it is permissible to ban the possession of handguns so long as the possession of other firearms (i.e., long guns) is allowed. It is enough to note, as we have observed, that the American people have considered the handgun to be the quintessential self-defense weapon. There are many reasons that a citizen may prefer a handgun for home defense: It is easier to store in a location that is readily accessible in an emergency; it cannot easily be redirected or wrestled away by an attacker; it is easier to use for those without the upper-body strength to lift and aim a long gun; it can be pointed at a burglar with one hand while the other hand dials the police. Whatever the reason, handguns are the most popular weapon chosen by Americans for self-defense in the home, and a complete prohibition of their use is invalid....However, even Justice Scalia and the four conservative Justices who signed onto his opinion recognized that said right was not absolute. Join me below the orange gnocchi:
First, the Court recognized that this right did not include all weapons:
Like most rights, the right secured by the Second Amendment is not unlimited. From Blackstone through the 19th-century cases, commentators and courts routinely explained that the right was not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose. For example, the majority of the 19th-century courts to consider the question held that prohibitions on carrying concealed weapons were lawful under the Second Amendment or state analogues....Secondly and importantly, the Court recognized that many longstanding restrictions on gun ownership and brandishing remained constitutional:
We also recognize another important limitation on the right to keep and carry arms. Miller said, as we have explained, that the sorts of weapons protected were those “in common use at the time.” We think that limitation is fairly supported by the historical tradition of prohibiting the carrying of “dangerous and unusual weapons.”
It may be objected that if weapons that are most useful in military service—M-16 rifles and the like—may be banned, then the Second Amendment right is completely detached from the prefatory clause. But as we have said, the conception of the militia at the time of the Second Amendment ’s ratification was the body of all citizens capable of military service, who would bring the sorts of lawful weapons that they possessed at home to militia duty. It may well be true today that a militia, to be as effective as militias in the 18th century, would require sophisticated arms that are highly unusual in society at large. Indeed, it may be true that no amount of small arms could be useful against modern-day bombers and tanks. But the fact that modern developments have limited the degree of fit between the prefatory clause and the protected right cannot change our interpretation of the right.
Although we do not undertake an exhaustive historical analysis today of the full scope of the Second Amendment, nothing in our opinion should be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms.And added in a footnote: "We identify these presumptively lawful regulatory measures only as examples; our list does not purport to be exhaustive."
The Court concluded:
We are aware of the problem of handgun violence in this country, and we take seriously the concerns raised by the many amici who believe that prohibition of handgun ownership is a solution. The Constitution leaves the District of Columbia a variety of tools for combating that problem, including some measures regulating handguns. But the enshrinement of constitutional rights necessarily takes certain policy choices off the table. These include the absolute prohibition of handguns held and used for self-defense in the home. Undoubtedly some think that the Second Amendment is outmoded in a society where our standing army is the pride of our Nation, where well-trained police forces provide personal security, and where gun violence is a serious problem. That is perhaps debatable, but what is not debatable is that it is not the role of this Court to pronounce the Second Amendment extinct.And that's where we are right now. The Court doesn't speak unless there is an active case or controversy before it—some statute or regulation whose constitutionality has been challenged—and it does not issue advisory opinions as to what might be constitutional. Those cases are bubbling up through the courts. Just last week, the United States Court of Appeals for the Seventh Circuit released its opinion in Moore v. Madigan, which concerned Illinois' unique restrictions on carrying a ready-to-use handgun outside the home. In that 2-1 decision, Judge Richard Posner expanded the Heller right to include self-defense outside the home as well, relying on the "keep and bear" language of the Second Amendment:
The right to “bear” as distinct from the right to “keep” arms is unlikely to refer to the home. To speak of “bearing” arms within one’s home would at all times have been an awkward usage. A right to bear arms thus implies a right to carry a loaded gun outside the home.
[A] Chicagoan is a good deal more likely to be attacked on a sidewalk in a rough neighborhood than in his apartment on the 35th floor of the Park Tower. A woman who is being stalked or has obtained a protective order against a violent ex-husband is more vulnerable to being attacked while walking to or from her home than when inside. She has a stronger self-defense claim to be allowed to carry a gun in public than the resident of a fancy apartment building (complete with doorman) has a claim to sleep with a loaded gun under her mattress. ... To confine the right to be armed to the home is to divorce the Second Amendment from the right of self-defense described in Heller and McDonald. It is not a property right—a right to kill a houseguest who in a fit of aesthetic fury tries to slash your copy of Norman Rockwell’s painting Santa with Elves. That is not self-defense, and this case like Heller and McDonald is just about self-defense.But even Judge Posner recognizes that different restrictions require different constitutional tests:
A gun is a potential danger to more people if carried in public than just kept in the home. But the other side of this coin is that knowing that many law-abiding citizens are walking the streets armed may make criminals timid. Given that in Chicago, at least, most murders occur outside the home, the net effect on crime rates in general and murder rates in particular of allowing the carriage of guns in public is uncertain both as a matter of theory and empirically
A blanket prohibition on carrying gun in public prevents a person from defending himself anywhere except inside his home; and so substantial a curtailment of the right of armed self-defense requires a greater showing of justification than merely that the public might benefit on balance from such a curtailment, though there is no proof it would. In contrast, when a state bans guns merely in particular places, such as public schools, a person can preserve an undiminished right of self-defense by not entering those places; since that’s a lesser burden, the state doesn’t need to prove so strong a need. Similarly, the state can prevail with less evidence when guns are forbidden to a class of persons who present a higher than average risk of misusing a gun. And empirical evidence of a public safety concern can be dispensed with altogether when the ban is limited to obviously dangerous persons such as felons and the mentally ill. Illinois has lots of options for protecting its people from being shot without having to eliminate all possibility of armed self-defense in public...It's time to explore more options, and there are many wise policies which would be perfectly constitutional to enact. Just last month, the Congressional Research Service published a guide to the state of play of current federal legislation and bills recently proposed. It's worth a read. Former Justice John Paul Stevens, now retired, addressed the Brady Campaign in a speech this October. In that speech he noted:
Apart from the usual prohibitions of gun ownership by children, felons, illegal aliens, lunatics, and in sensitive places such as public schools, the propriety of which was not questioned in Heller, some states sensibly require that an applicant for a handgun permit establish his competence in handling firearms. A person who carries a gun in public but is not well trained in the use of firearms is a menace to himself and others.
While the post-decision commentary by historians and other scholars has reinforced my conviction that the Court's decision to expand the coverage of the Second Amendment was incorrect,  good things about the Court's opinion merit special comment.... [T]he Court did not overrule Miller. Instead, it "read Miller to say only that the Second Amendment does not protect those weapons not typically possessed by law-abiding citizens for lawful purposes, such as short-barreled shotguns." On the preceding page of its opinion, the Court had made it clear that even though machine guns were useful in warfare in 1939, they were not among the types of weapons protected by the Second Amendment because the protected class of weapons was limited to those in common use for lawful purposes like self-defense. Even though a sawed-off shotgun or a machine gun might well be kept at home and be useful for self-defense, neither machine guns nor sawed-off shotguns satisfy the "common use" requirement. Thus, even as generously construed in Heller, the Second Amendment provides no obstacle to regulations prohibiting the ownership or use of the sorts of automatic weapons used in the tragic multiple killings in Virginia, Colorado and Arizona in recent years. The failure of Congress to take any action to minimize the risk of similar tragedies in the future cannot be blamed on the Court's decision in Heller.