federal government have constitutional rights" is accurate and correct. You have just agreed with that.
I have never held that they have the same exact rights, as I even stated in this thread here:
http://tigerboard.com/boards/view.php?message=14758892
However, the most important rights (those found in the Bill of Rights) do apply to all persons - citizens or otherwise - who come into contact with the federal government.
Glad you agree that all persons who have contact with the federal government have constitutional rights.