If I were really a cynic...

...I would argue that the 7th Circuit Court upheld Chicago's ban on handguns because hey, somebody's gotta stand up for the well being of their thug cops. Can't have the subjects able to actually defend themselves against those assholes, you know.
Seriously though, if you read the decision you see one of the judges actually acknowledge we live in a federal republic. Such a shame anyone would use that to justify infringement of any right, though...