Professor Rosenthal filed a brief in the United States Court of Appeals for the Seventh Circuit on behalf of the U.S. Conference of Mayors in McDonald v. City of Chicago, an appeal presenting the question whether the right to bear arms found in the Second Amendment to the United States Constitution applies to state and local gun control laws. The brief takes the position that in order to effectively combat gang and drug crime, state and local government needs the freedom to use gun control laws as long as they do not completely prohibit the possession of firearms useful for purposes of self-defense.