Well, as an attorney, I would say that Cooleys position still holds.
Specifically, in 2008, in the case of District of Columbia v. Heller, the SCOTUS for the first time invalidated a law regulating guns and found that the Second Amendment is not limited to protecting a right to have firearms for militia service. This case concerned the constitutionality of a 32-year-old District of Columbia ordinance that prohibited the possession of handguns and imposed significant restrictions on long guns. The SCOTUS, in a 5-4 decision, invalidated the ordinance as it violates the Second Amendment.
I rest my case. :-)
They later expanded upon it in McDonald v City of Chicago.
L