You would think it would. But they play these games at the border where x amount of distance (something 500 or 1000 feet) on either side of the border is "a no man's land" and same thing at international arrival areas at airports. Its not US territory, nor is it Canadian or Mexican territory for the land borders and as such claim your constitutional rights aren't in effect there. This is why they can ask all the questions they want, search your car, detain you and all that other good stuff and not "violate" the Constitution. Hell, there is some 100 mile rule they can operate in from any of the borders where they can intercept and detain you for whatever border related issue they can come up with. Ideally, if you are an American Citizen and are coming back back to the US across one of these borders your Constitutional rights should immediately be in effect when dealing with US Customs and Border Patrol. But, the cowards of the country would rather give up their Constitutional rights for security theater.