Sorry but you guys are missing the big point. The Constitution only applies to US citizens, to protect our rights.
This is of course what Eric Holder was trying to do with the terrorist trials, apply Constitutional protections to foreigners which is very wrong.
The border people are there to protect out borders and to control who comes in. I would expect the Canadians to do the same for their border. They had every right to ask where he was going and see how he answered.
No, the Constitution delineates what the Federal government can and CANNOT do to protect our rights.
Read the Bill of rights and you’ll see that a FULL SIXTY percent deal with property-rights; more specifically, the intersection of property-rights and the government.
According to your theory it would be perfectly Constitutional for the border-guards to steal the ID, money, keys and even clothes from someone wanting entry to the country before turning him back.