Two years ago, the Supreme Court struck down parts of the District of Columbia’s gun-control law. On Tuesday, the court will consider whether that decision should apply everywhere in the country, not just in the federal territory of the nation’s capital.

We disagreed strongly with the 2008 decision, which took an expansive and aggressive view of the right to bear arms. But there is an even broader issue at stake in the new case: The Supreme Court’s muddled history in applying the Constitution to states and cities. It should make clear that all of the protections of the Bill of Rights apply everywhere.

McDonald v. Chicago is a challenge to a law that makes it extremely difficult to own a handgun within Chicago’s city limits. The challengers rely on the court’s 5-to-4 ruling in 2008, which recognized an individual right under the Second Amendment to carry guns for self-defense. But that decision left open an important question. The Bill of Rights once was largely thought to be a set of limitations on the federal government. Does the right to bear arms apply against city and state governments as well?

Since states and localities do far more gun regulation than the federal government, the court’s answer will have a powerful impact. The United States Court of Appeals for the Seventh Circuit, in Chicago, relying on 19th-century precedents, ruled that the Second Amendment does not apply to states and cities.

Under the doctrine of “selective incorporation,” the Supreme Court has ruled on a case-by-case basis that most, but so far not quite all, of the Bill of Rights applies to states and cities. The court should dispense with the selectivity and make clear that states and cities must respect the Bill of Rights.

To justify incorporation, the court has relied on the 14th Amendment, which was enacted after the Civil War to ensure equality for newly freed slaves. The amendment has two relevant clauses: the due process clause that requires government to act with proper respect for the law, and the privileges or immunities clause, which is more focused on protecting substantive individual rights.

The logical part of the amendment to base incorporation on is the privileges or immunities clause, but a terrible 1873 Supreme Court ruling blocked that path and the court has relied since then on the due process clause.

A group of respected constitutional scholars and advocates is asking the court to switch to the privileges or immunities clause as the basis for applying the Bill of Rights to states and cities. That would be truer to the intent of the founders, and it could open the door to a more robust constitutional jurisprudence that would be more protective of individual rights.

It is unlikely that the court will delve directly into the gun issues. If it decides to apply the Second Amendment to cities, it would probably send the case back to a lower court to evaluate the Chicago law. If that happens, the justices should guide the court in a way that makes clear that reasonable gun restrictions will still be upheld.

The Supreme Court’s conservative majority has made clear that it is very concerned about the right to bear arms. There is another right, however, that should not get lost: the right of people, through their elected representatives, to adopt carefully drawn laws that protect them against other people’s guns.

Read the original editorial here.