Opponents of gun control argue that it does not address the problem of illegal weapons. If you make it harder for people to obtain guns legally, they claim, then it simply increases the demand for illegal guns, with potentially deadly consequences.
American citizens have the constitutional right to bear arms, and they should not have to resort to breaking the law in order to exercise that right. Yet that is precisely what would happen, so the argument runs, with any system of gun control. Far better to allow people to obtain weaponry legally, at licensed gun stores, than to encourage, albeit inadvertently, the dangerous practice of buying them on the black market. Apart from anything else, the illegal gun trade creates a huge business opportunity for organized crime, not to mention terrorist groups eager to get their hands on some ready cash to fund their various operations.