Saying Jersey, the difference is between optional and mandatory.
If there was the option for "smart" guns to be sold alongside regular guns I doubt you would have heard a peep from the NRA, besides maybe a review in guns and ammo. But New Jersey decided that the moment a smart gun becomes available it must be mandatory on every weapon sold, then it becomes a matter of force vs choice. Repeal that little law and those who chose to use the smart guns can have them, while everyone else can purchase weapons with traditional safeties.