Today, the Supreme Court will take up the potentially historic case of McDonald v. Chicago on gun rights. There is more at stake than just the application of the Second Amendment to the states, as I discussed in today’s column in Roll Call below:

Across the country, city and state officials are watching nervously as the Supreme Court takes up a case today that could effectively gut many gun control laws.

At issue in McDonald v. Chicago is whether the court’s earlier recognition of an individual’s right to bear arms applies not just to the federal government but also to the states. Since most rules affecting gun ownership are municipal and state laws, the decision could make it difficult to ban outright possession of handguns and other types of weapons. However, there is an even more significant constitutional question in the case that could have ramifications far beyond gun rights — an issue that has divided both the liberal and conservative alliances in the case.

The most immediate issue in the McDonald case is the viability of thousands of gun laws across the country. Many gun owners were in for a rude awakening after the 2008 decision in District of Columbia v. Heller. Gun owners were ecstatic after the court ruled that the Second Amendment protects not just the right of states to maintain militias but the right of individuals to possess firearms. They then learned, because of a long-standing interpretation of the Bill of Rights under the Slaughterhouse Cases from the 19th century, that the court’s ruling would bind only the federal government.

To apply to the states, the court has to make the separate determination that this right is so fundamental that it should apply to the states. The court’s selective incorporation of some, but not all, rights in the Bill of Rights is one of the longest-standing controversies in constitutional law — almost as long as the controversy over the meaning of the Second Amendment itself.

That issue has divided both the liberal and conservative communities — much like the recent Supreme Court decision in Citizens United on campaign finance.

While gun control is usually a reliable rallying point for the right and left, there is a major complication in the case over the court’s practice of picking and choosing which rights in the Bill of Rights are applied to the states. Many civil libertarians are not thrilled over gun rights but want the court to use the decision to finally rule that all of the rights contained in the Bill of Rights apply to the states with no exceptions. Conversely, many conservatives want the gun rights but do not want the expansion of rights that apply to the states under the Bill of Rights.

Any way this case goes, it will be historic. Even under current case law, the court is likely to find that Second Amendment right does apply to the states. It would certainly make it harder for states to restrict gun ownership. It will not mean that states can place no restrictions on gun possession or ownership. Even First Amendment rights have some limitations. The incorporation of the Second Amendment would make the right of gun ownership comparable to the right of free exercise of religion.

The court should go further, however, and change not just the status of gun rights but rights generally. The court should remove the current firewall between the application of federal rights to the states — creating a unified base of rights for all citizens. This is why some conservatives want to change the status of gun rights but not the Bill of Rights. They fear that future federal rulings could favor gay couples or other groups and then bind the states.

While this concern is overblown (because the expansion of such fundamental rights would likely be incorporated to the states under the current rule), it is true that full incorporation of all rights would create one definition of rights for all citizens regardless of where they live.

Many briefs in the case are gunning for the overturning of the Slaughterhouse Cases where the court in 1873 gave itself the role of determining which rights would apply to the states.

If the court overturned the Slaughterhouse Cases (as requested by many civil libertarians), it would be a victory for one of the greatest justices in the court’s history, Hugo Black, who fought for full incorporation. Black was right, and, more than 60 years after his defense of the Bill of Rights and 136 years since the ruling in the Slaughterhouse Cases, we should finally get it right.

Moreover, conservative justices could prove that they have a broader vision of individual rights that goes beyond the barrel of a gun. The right to gun ownership should apply to the states not because it is more important than other rights but because it is part of the Bill of Rights. We should no longer follow a constitutional version of the law of “Animal Farm” that all animals are equal but some animals are more equal than others. All rights of the Bill of Rights should be equal and no rights more equal than others.

A ruling overturning the Slaughterhouse Cases would show liberals that the court is not simply handing insular victories to favored groups but carrying out a more deep-seated jurisprudence. The Bill of Rights is part of the privileges of all citizens and no state should be able to abridge those rights.

After all, the Bill of Rights is what defines us as a people. We carry it with us like a membership card applicable at any time in any state. While we can disagree on the meaning of the Second Amendment, we should agree that all citizens — whether in Alabama or New York or Texas — should receive the full benefit of all the rights contained in the Bill of Rights because they are all (first and foremost) Americans.

Jonathan Turley is the Shapiro professor of public interest law at George Washington University and a frequent witness before Congress on constitutional matters.