The Second Amendment prevents the federal Congress from infringing on the rights of citizens to bear arms. At the same time, up until 1925, the federal Constitution, including its amendments, was understood to constrain the powers of the federal government only. That is how, for example, slave states were able to deny civil rights to blacks, but presumably it also allowed states and local governments to exercise whatever control they wished over local residents’ rights to possess weapons. In 1925, however, the Supreme Court decided that the 14th amendment required “incorporation” of the Bill of Rights into state law. This included the Second Amendment, a point which was recently clarified in 2010 by the Supreme Court in McDonald v Chicago.
Many gun-control advocates would probably wish we could return to the old federalism when it comes to the right to bear arms; however, they cannot return the power to control guns to states without also returning the powers to deny due process, suppress free speech, or revoke any of the other rights protected in the Constitution. As a libertarian and believer in natural rights, I mostly welcome this restriction on state and local powers from infringing on natural rights; at the same time, I sympathize with the notion that different communities may even disagree on what constitutes a natural right.
The right to bear arms does seem to be one of those rights that many deny exists. While no one denies the natural right to self-defense, many balk at extending that right to carrying firearms. My response to this is that the individual has a right to any effective form of defense, and for many, the most effective form of defense is the handgun. I’m sure even the most pro-gun advocate would not claim that an individual needs a right to possess his own nuclear arsenal, since there is no sense in which a private citizen needs those kinds of weapons to defend himself and his household. But handguns may be the only thing that works against violent intruders, whereas knives or his own fists and feet may not be adequate.
That being said, should states be allowed to decide differently on this question? I would say that, if states have the power to deny private citizens the right to bear arms in self-defense, they should also have the power deny all other rights. If we allow disagreement over one right, why not allow disagreement over the others?