I think voting rights should be tied to returning carts to the little cart thing. It's such a simple act that provides almost no personal benefit to the person doing it (apart from just "doing the right thing"), but in my mind the kind of person who does it is being respectful and considerate of their fellow person. People who don't return the carts and just leave them sitting around are trash and shouldn't have any say in how the rest of society functions (handicapped folks would obviously get a pass).