“When you come back into the United States with a United States Passport, you are an American citizen on American soil. I’m not sure how we American citizens ever gave up our rights under the fourth amendment”
FRiend, by law the port of entry is not “american soil” until you prove your citizenship/status and the officer decides to let you in.
Period!
If you present a valid US Passport, the only thing your beloved "officer" has any say in as to whether it is indeed your passport. If he has probable cause to believe it is not, then he may detain you for that reason and that reason alone. When one comes back into the US, the Immigration folks check your Passport. It's the Customs folks who think they have some right to search you. You don't get to them until after the Immigration guy has waived you through.
ML/NJ