“ In the present case a ground far narrower than that on which the Court of Appeals rested its decision, the defense of qualified privilege, was consistently pressed in the District Court and in fact urged in the Court of Appeals itself. In these circumstances we think that the broad requirements of judicial power and its proper exercise should lead to consideration of the defense of qualified privilege. ”

“ Likewise, 'Courts should avoid passing on questions of public law even short of constitutionality that are not immediately pressing. Many of the same reasons are present which impel them to abstain from adjudicating constitutional claims against a statute before it effectively and presently impinges on such claims.' Eccles v. ”