Donald Sensing makes the point that concealed carry proponents who argue that CCW permits can reliably prevent mass shootings. He makes some good points, but a sizeable part of his argument is based on the fact that lots of people with permits don't actually carry very often. This is, I think, self-evident. Apart from my wive's brothers (a sherrif's deputy and a prosecutor who are armed pretty much at all times including our wedding, their weddings, etc.) I know very few people who carry consistently.
However, I note that a lot of the reasons he brings up that people don't carry involve the fact that it's still illegal to carry in lots of places even if you have a permit. Due to the hassle involved, lots of people carry infrequently.
It seems to me though that the people who believe CCW permitting will solve a lot of problems would also argue that people with CCW permits should be able to carry pretty much anywhere.