When I was in Mexico it was far, far worse than the way Hollywood portrays the 1870’s wild, wild west. It was obvious that if Mexicans were allowed to carry concealed that the violence would be reduced. The bad guys ride up and down the street shooting people. (While I was there they killed four school kids in their uniforms in a drive-by.) Just after I left there was a two hour shootout between gangs in a major shopping mall. (I’d been to that mall.) If everybody had the right to guns that shootout would have been considerable shorter or, more likely, would not have happened in the first place.
Jessie James’s gang was essentially ended by the citizens of a small town who all ran to the bank he was robbing and opened fire on him. (Yeah, it did go on for a short time after that, but that was essentially his finish.)
Believe me, the Chicago area is chock full of Mexicans, and they are ALL armed. Mexican gangs are the dominant gangs in the Chicago area. The Mexican drug cartels call most of the shots in the Chicago area.