Some college professors in Texas want to allow concealed carry on campuses, except in dorms, because that would just be silly.
Keep in mind that during the Virginia Tech shootings, the first shootings happened in a dorm. The shooter then went to an academic building, chained the exits, and proceeded to go on his rampage.
The problem with concealed carry isn’t the concealed carriers. It’s all the bullets they would fire at the unknown shooter, or at the kid who was carrying a stapler and dressed in dark clothes. You know, whatever. It’s highly unlikely that concealed carry would make mass shootings more likely – it is, however, highly likely that when someone is insane enough to decide they want to kill a few dozen people, a disorganized, untrained armed response is likely to make the situation far more dangerous to all involved.