Where do our federal constitutional protections from conduct by state and local actors come from? Mostly, through incorporation of the Bill of Rights via the due process clause of the 14th Amendment.
Another route to secure a similar result, via the privileges and immunities clause of the 14th Amendment was considered and rejected in the Slaughterhouse cases. A new article by Larry Solum, the proprietor of the Legal Theory blog, offers some thoughts about what it would mean if the privileges and immunities clause rather than the due process clause of the 14th Amendment were used as the theoretical basis for incorporation of the Bill of Rights. This has been discussed as a step that the court could take in deciding whether to apply the Second Amendment to the states.
Some of the observations made include:
1. The privileges and immunities clause confers rights only on U.S. citizens, not all persons. Thus, legal and illegal immigrants could lose many of their constitutional right under this approach. This also opens a new door to denying constitutional rights to felons whose other citizenship rights are limited by their convictions.
2. The privileges and immunities clause has the potential to provide a stronger legal justification to substantive due process cases like Roe v. Wade, since it has a meaning in the legal community when the 14th Amendment was adopted that included multiple unenumerated rights.
3. This article doesn't discuss, but I've previously noted that this would also be a time when the Supreme Court could move from a selective incorporation to a total incorporation theory with regard to the Bill of Rights. This would make the right to a unanimous criminal jury (not currently available in Louisiana and Washington State), the right to have capital and infamous crimes screened by a grand jury (something now present in only about half of the states), and the 7th Amendment right to a civil jury trial, matters of constitutional stature.
Incorporating the Second Amendment is a not the best option. Gun control is best left to individual state and local governments to decide. The Second Amendment should simply prevent the federal government from nationalizing the gun control issue.
There may be room to articulate new unenumerated rights particular to U.S. citizens under the privileges and immunities clause, or to provide an additional basis for the constitutional rights of U.S. citizens vis-a-vis the U.S. government outside the territory of the United States and in parts of the United States that are not within any state. But, it does not make sense to reverse decades of precedent to use this as a primary way to apply provisions of the federal bill of rights to the states in a way that denies rights to people who aren't U.S. citizens when those rights don't obviously have a connection to U.S. citizenship.