Retired/Offduty LE, retired military and teachers as long as they could legally own a firearm and recieved the proper training.
The strangest argument I heard against this is, “the kids would feel like they are in prison.” I wonder what a school lockdown makes them feel like.
It seems to me that there are a lot of Hoplophobiacs around.
Seriously it seems to me that anyone who passes the FBI background check and gets the proper training should be allowed to carry a firearm wherever and whenever they want. It would certainly cause criminals to pause and wonder just who they are going to meet when they are out and about doing their criminal business.