increased gun ownership may reduce home invasions and stick ups, but drive bys and other random shootings probably wont be impacted.
gang assassination attempts that get innocent people caught up are not going to be prevented by knowing some people are carrying, the gangster thinks he is shooting at other gangsters who are likely armed, and they do it anyway because they have the element of surprise. unless the shooter is terrible, no armed victim is going to be able to even use his gun in self defense.
they are going to have to solve chicago's gang problem directly somehow, but i dont oppose this measure, chicago cant get any worse anyway