proceeding relating to a municipal district in Texas had declared the statute under which the District Court had acted to be unconstitutional. Ashton v. Cameron County District, 298 U. S. 513. In view of the importance of the question we granted certiorari. October 9, 1939.
The courts below have proceeded on the theory that the Act of Congress, having been found to be unconstitutional, was not a law; that it was inoperative, conferring no rights and imposing no duties, and hence affording no basis for the challenged .decree. Norton v. Shelby County, 118 U. S. 425, 442; Chicago, I. & L. Ry. Co. v. Hackett, 228 U. S. 559, 566. It is quite clear, however, that such broad statements as to the effect of a determination of unconstitutionality must be taken with qualifications. The actual existence of a statute, prior to such a determination, is an operative fact and may have consequences which cannot justly be ignored. The past cannot always be erased by a new judicial declaration. The effect of the subsequent ruling as to invalidity may have to be considered in various aspects, — with respect to particular relations, individual and corporate, and particular conduct, private and official. Questions of rights claimed to have become vested, of status, of prior determinations deemed to have finality and acted upon accordingly, of public policy in the light of the nature both of the statute and of its previous application, demand examination. These questions are among the most difficult of those which have engaged the attention of courts, state and federal, and it is manifest from numerous decisions that an all-inclusive statement of a principle of absolute retroactive invalidity cannot be justified.3 Without attempting
3
See Field, “The Effect of an Unconstitutional Statute”; 42 Yale Law Journal 779; 45 Yale Law Journal 1533; 48 Harvard Law Review 1271; 25 Virginia Law Review 210.