We also needed that super-majority to over ride home rule for places like Chicago and Oak Park.
This proposal may have an effect of rousing some of the complacent hunters and gun owners to action, we have yet to see what the backlash is going to be.
The mayor is elected by people in the city obviously, but a suddenly uncooperative Illinois State legislature can cause Chicago and the mayor a lot of pain.
It seems like a sensless way to expend political capital, but it may be ideologically motivated, or maybe President Obama asked Rahm if he could do something to try to lend weight to the idea that lack of gun control laws is a serious problem in the country? Like maybe adding weight to the argument that even if Fast & Furious was executed poorly, the premise of it was valid - lax gun control laws cause violent crime.
I don't know... I'm just speculating, but I don't think that there would be any big payoff from Rahm's constituents for proposing gun control - there is very little upside to it and a tremendous potential downside.