28 U.S. Code § 2201
a) In a case of actual controversy within its jurisdiction, (...) any court of the United States, upon the filing of an appropriate pleading, may declare the rights and other legal relations of any interested party seeking such declaration, whether or not further relief is or could be sought.
And Rule 57, which you cited, says the following:
A declaratory judgment is appropriate when it will "terminate the controversy" giving rise to the proceeding. (...) The "controversy" must necessarily be "of a justiciable nature, thus excluding an advisory decree upon a hypothetical state of facts." (...) The petitioner must have a practical interest in the declaration sought and all parties having an interest therein or adversely affected must be made parties or be cited.Â
So again, federal courts will not issue a declaratory judgment unless there is an actual case or controversy involving the requesting party, as opposed to a theoretical controversy.
It doesn’t have to be a case, and clearly there is a controversy.
It doesn’t have to be a case, and clearly there is a controversy.