Illinois State Senator Donne Trotter has long opposed the idea of allowing civilian concealed carry in his state. During a 1995 hearing on the matter, he had this to say:
There's a lot of individuals out here who do look at this as an opportunity to be that vigilante, to be that support person to the police officer who isn't there, which is one of the things we addressed just yesterday (…) What you're doing here just basically creating part-time police officers who have not gone through the extensive training, who have not had the psychological evaluations, who will be getting out there who feel now that they're–they are stronger, they are badder, they are tougher because they have this nine-shooter on their hip.
…and on Wednesday, he was arrested for attempting to bring a concealed handgun through security at O'Hare airport.
This one really speaks for itself, so I'll just leave it at that.