It doesn't, but it's well established laws that certain protections don't exist when you cross an international border because the government has a responsibili

It doesn't, but it's well established laws that certain protections don't exist when you cross an international border because the government has a responsibility to maintain security at the border and manage imports/exports. They can't do that if they don't have some rights to search. But that said, I would agree that carte blanche right to "inspect" an electronic device seems overly intrusive. It's not like the government can require a bodily cavity search at the border, so clearly there are limits that require a warrant.