A member of the travelling public has not demonstrated probable cause for an unwarranted, unreasonable search of his/her possessions or being.
The probable cause requirement applies to the issuance of a warrant (and arrest without a warrant). Probable cause can also give the right to search without a warrant. Articulable reasonable suspicion can give the right for an investigative detention and a protective frisk. Finally, searches based on consent (either express or implied) do not need any probable cause or suspicion whatsoever.
Libertines want to read things into the Constitution that are not there. These people are as great a threat as far-left liberals who also want to read things into the Constitution that are not there. The moment we begin adding things into the Constitution that don’t exist, (such as a right to fly) then the Constitution becomes meaningless.