The war on drugs, which led to extraordinary harm to many people and communities, could certainly be categorized as extreme and unpopular. Could you elaborate on what you mean?
I just realize you mean that they use their power to not enforce something when that thing is "very often extreme, and unpopular. " The way you said it "The cases where they exercise this power are very often extreme, and unpopular." seemed to me to indicate that their choice to enforce their action was extreme or unpopular.
