Because no one seems to know how the Branches of government works!
The Constitution is just a minor inconvenience.
Plus, no one in these states government have been arrested for breaking Federal laws!
Locking up these mayors, police chiefs and governors would send a strong message!
The law has to be challenged in a court of law.
Bringing a law suit after your guns have been confiscated is a VERY expensive proposition.
Some deep pocketed organizations will need to step in and challenge the law, and to date, none have.
Where are you NRA? GOA? VCDL? JFPO? NAGR?