The Constitution applies to the U.S. government and to the citizens of the united states. It does not include geographic limitations of any kind. All of this making borders a Constitution free zone is completely unConstitutional. I don't care if the ground I am standing on is legally considered to be the Greater 2nd Empire of Mars, I am still a U.S. Citizen and the border guard is still a representative of the U.S. government. The Constitution applies. Obviously it isn't being respected, but it certainly applies.