This argument is somewhat incomprehensible. It posits that people who are born and live in the United States are somehow not citizens of it, but have some sort of free-floating “sovereignty” that protects them from any government action they don’t like.

The short answer to this argument is found in the 14th Amendment to the Constitution of the United States, which provides that “[a]ll persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.” This constitutional provision shows that most Americans have two citizenships: each American is a citizen of the state wherein he or she resides and also a citizen of the United States. The fact that you may be a citizen of Texas or Montana, for example, does not prevent you from also being a citizen of the United States.