...I'm pretty confident there was at least one ... at that club who would have been armed if it weren't a state mandated "gun free zone". It may not have had a difference, but that's not the point.
Good point, but I'll add that it's not supposed to make a difference to the body count, save one: the person who has a chance to save themselves. Any other lives saved is just pure gravy, and at the responsibly-armed person's discretion.