(Credit: Getty/Photo Montage by Salon) American cities have become increasingly liberal, while the Republican Party controls most state governments. In an effort to keep blue cities from passing local ordinances reflecting their values, Republicans legislators in state capitals have embraced pre-emption laws, preventing city governments from enacting all kinds of things: Protecting their residents from discrimination, for instance, or increasing the minimum wage. Now Republicans in the Arizona state legislature are using that power to protect the flow of dark money — cash spent on campaigns from secret donors — into state and local elections.