It turns out, you're right. "Black flight" (black people moving out of multi-ethnic or predominantly black areas to areas with a higher white population) is just as much of a phenomenon as "white flight" (white people moving out of multi-ethnic or predominantly black areas to areas with a higher white population). Then, the question should probably be, what makes a nation to begin with? At its most extreme, maybe we could all adopt a new language. Maybe we could learn Pennsylvanian Dutch, and join the Amish. I'm not convinced that we can feasibly take over the state, personally, but maybe there are barriers we can implement to secure our autonomy.