Miami is run almost as a city-state. The local government refuses to pay their state taxes. As a result, the State of Florida has cut off all state funded services. This suits Miami just fine. The population is made mostly of the upper class who are fine paying higher city taxes to fund such services locally.
Miami is a very clean city. Garbage is picked up in the downtown streets nightly, all city workers are expected to wear clean and pressed uniforms, and the cops crack down hard on littering and vandalism.