How many of "the People" of the United States are required to alter or abolish the government? Can an individual declare himself to be another country? What about a city block? A county? Is it only states? What about the fact that some counties have populations and areas larger than some states?
I have a reading assignment for you:
The Declaration of Independence and the Constitution of the United States by The Founding Fathers.
A Constitutional History of Secession by John Remington Graham.
Rethinking the American Union for the Twenty First Century edited by Donald Livingston.