That’s been happening in Atlanta / Fulton County for the last few years. Several areas have seceded from the city because they were paying taxes used to buy votes in the poor areas.
http://en.wikipedia.org/wiki/Secession_in_New_York
There are or have been several movements regarding secession in the U.S. state of New York.
The most prominent amongst these have been for a state called Long Island, consisting of everything on the island outside New York City; a state called Niagara, the western counties of New York state; the northern counties of New York state called Upstate New York; making the city of New York a state; a proposal for a new Peconic County on eastern Long Island; and for the boroughs of Staten Island and Brooklyn to secede from New York City.