text: I'm so glad you included that "due process of law" thing, because that is an Constitutional right.  That isn't a license, that is the exercise of that very right.  Due process, that thing that the government MUST do to insure an individuals rights are not violated.  Requiring a license for something that is an enumerated right, is not due process.  It is against the Constitution to "chill" those rights by licensing their use.