Hoppe is an anarchist and doesn't believe in a national will. He certainly doesn't believe in using the power of a nation state to crush the expressed desires of a community. His point about open vs closed borders is that the state shouldn't be making this choice at all. It should be private property owners but the state prevents that. The second best, then, is the nearest approximation to what private owners would do, which is locally expressed political preferences that are often exclusionary. There's nothing in Hoppe's writing that supports an outside group invading a community and forcing a policy regime on them.