Over the Christmas season, the Transportation Security Administration (TSA) quietly announced that America was walking down that path. By 2016, all domestic air travel will require either a traditional passport or a federally-compliant ID card called "Real ID." State driver's licenses will no longer allow Americans access to domestic flights, as they do now. Real ID will constitute an internal passport. (The drop-date date is commonly reported as January.)
An internal passport refers to an identity document that people must produce to move from place to place within national borders. It allows a government to monitor the movement of its own people and to control that movement by granting or denying ID. In the past, governments have used internal passports to isolate 'undesirables', to regulate economic opportunities, to reap personal data, to intimidate and command obedience, and to segregate categories of people (like Jews) for political purposes. It allows a government to bind anyone it chooses to his or her place of birth.