The Supreme Court has long recognized a border-search exception to the Fourth Amendment’s warrant requirement. In United States v. Flores-Montano, the Court looked to the nation’s sovereign “interest in protecting . . . its territorial integrity” to justify such searches.3 In United States v. Montoya de Hernandez, the Court stated, somewhat more narrowly, that Congress is the source of the executive’s power. It explained that “[s]ince the founding of our Republic . . . [Congress has] granted the Executive plenary authority to conduct routine searches and seizures at the border, without probable cause or a warrant.” The Commerce Clause permits Congress to authorize the seizure of goods at the border.
https://yalelawjournal.org/forum/customs-immigration-and-rig...