On March 2, the nine justices of the United States Supreme Court met to argue about whether the State of Illinois can constitutionally ban handguns in the City of Chicago. This landmark case will not only affect gun rights, but also will determine how the Supreme Court goes about telling states and localities what they can and cannot do under the Fourteenth Amendment of the Constitution.

By all indications, the Court will soon order Chicago to lift its handgun ban, but lawyers opposing the ban are deeply divided about which part of the Fourteenth Amendment the Court should invoke. The Court’s choice about which clause of the Fourteenth Amendment to use is critically important, because that choice will likely determine the high court’s path for decades to come.

One of the two clauses at issue from the Fourteenth Amendment is this one: “No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States.” This clause comes into play because the Court already decided a couple years ago that the national government of the United States may not infringe a citizen’s right to keep and bear arms; the Privileges or Immunities Clause would extend these gun rights so that they also apply against states like Illinois.

The other clause at issue from the Fourteenth Amendment is this one: “nor shall any state deprive any person of life, liberty, or property, without due process of law.” This clause essentially addresses HOW people can be deprived of life, liberty or property rather than WHETHER people can be deprived of life, liberty or property. Nevertheless, the Court has used a controversial interpretation of this clause called “substantive due process” in order to protect the right of free speech (enumerated in the Constitution), the right of abortion (not enumerated in the Constitution), and many others, potentially including gun rights too. The Court’s liberal justices have enjoyed using substantive due process instead of the Privileges or Immunities Clause because substantive due process gives the Court flexibility to apply against the states unenumerated rights that do not already apply against the national government of the United States.

During the March 2 arguments, Justice Stephen Breyer argued that this gun case would involve an extreme use of substantive due process, because there is not only a liberty interest in gun possession on one side of the case, but also there may be an interest in “life” on the other side of the case. Of course, the liberal Justice Breyer has in the past not been shy about using substantive due process to impose his own views with regard to competing liberty interests. However, he is correct that the conservative justices’ use of substantive due process in this gun case would be among its most controversial uses, portending an even more aggressive use of the doctrine from the liberal side. The losers would then be democracy, self-government, constitutionalism, the rule of law, and federalism.

During the arguments on March 2, conservative Justice Antonin Scalia strongly hinted that he would grudgingly use “substantive due process” in this gun case even though he thinks it is wrong, in order to mimic the liberal justices’ use of that doctrine. If that is how the cookie crumbles, then the Constitution will crumble a bit too.

As if Scalia’s comments were not dispiriting enough, the usually astute Chief Justice John Roberts announced that the Privileges or Immunities Clause would give liberal judges “a lot more flexibility than due process.” Roberts has it backward, though; as mentioned above, the judicially-created fiction of “substantive due process” allows liberal judges to apply rights against the states even including rights that are not already enforceable against the federal government, whereas the plain text of the Privileges or Immunities Clause avoids such limitless flexibility.  Obviously, a “privilege or immunity of citizens of the United States” cannot mean something that the federal government is free to violate.

Instead of mimicking the liberal justices, the conservative justices ought to show how a constitutional government actually works. The doctrine of substantive due process is a lie, and the Privileges or Immunities Clause means what it says.

P.S. I am counsel for the group Arms Keepers, which filed two friend-of-the-court briefs in the case of McDonald v. Chicago, one asking the Supreme Court to hear the case, and the other arguing the merits of the case. I attended the oral argument on March 2, 2010.