The Assault Weapons bad was a bad idea, and it seems immensely likely that whatever new (or old) ideas they put forth will at least be as equally boneheaded.
It is illegal to kill someone in cold blood. Anyone not deterred by their own morals or the law against murder would almost certainly not be deterred from picking up a rock and caving in someone's head by a second law that makes it illegal to kill with a rock. The rock law, in gun control terms, only assures that the potential law abiding victim will not be able to defend themselves.
Video embedded below.