Before a lawsuit is justiciable under Article III of the Constitution, there must be a genuine controversy appropriate for judicial resolution. There must be a concrete adversity of interest between the opposing parties, because an Article III court may not decide a collusive suit or render an advisory opinion. Accordingly, courts must insist that the real party in interest challenging the Executive Branch’s position not itself be an agency of the Executive Branch. In this way, courts will avoid hearing potentially collusive lawsuits and performing functions committed by the Constitution to the President.
There are no cases in which disputes between two agencies, both of whose heads serve at the pleasure of the President, have been found to be justiciable. In two recent Superfund enforcement actions initiated by the Environmental Protection Agency, the defendants attempted to join other federal agencies as co-defendants. In both cases, the courts rebuffed the attempts on the ground that the United States may not sue itself. Accordingly, a suit brought by the EPA against the Department of Energy, or any other Executive Branch agency whose head serves as the pleasure of the President, would be nonjusticiable.