In California, a simple battery costs one's 2A right for ten years. A battery is not even a crime of moral turpitude.
However, in a post-incorporation world, CA would justify this prohibition in the same manner the feds will on remand in this case.
They would say a person convicted of DV has shown a willingness to engage in unwarranted violence. This justifies the need for the state to deprive him of his right to a weapon.
I think the problem with the case was that the feds never attempted to justifiy the statute.
My own personal opinion is that only felons at common law should be deprived of 2A rights. Nowadays, govs call the most innocuous of offenses felonies, thereby undermining the 2A, to the point that some day it may be a felony to litter.