It must; the restraints of the Constitution are obviously on the government, not the people.
Until I have passed through customs, I am not legally in the USA and therefore the 4th Amendment does not apply. Unless for some odd reason you think the Constitution applies throughout the world.
Question: if you are traveling abroad, and the US Government decides that you've committed a crime, can it kill you in contravention to the 5th and 6th amendments which guarantee: due-process of law, that all prosecution of capitol offenses be validated by presentment/indictment of a Grand Jury, that the accused should have jury trial where the offense occurred, that the accused should be "informed of the nature and cause of the accusation", and that he should be able to mount a defense?
I’ve been waiting close on two hours for some evidence that 4A warrant requirements have EVER been considered as applying to customs inspections.
I guess I’ll have a long wait.