proponents contend that congress has the power to pass whatever copyright term it wants because the language "to promote the progress of science and useful arts" in the united states constitution is not a substantive limitation on the powers of congress, leaving the sole restriction that copyrights must only last for "limited times." however, in what respect the granted time must be limited has never been determined, thus arguably even an absurdly long, yet finite, duration would still be a valid "limited time" according to the letter of the constitution as long as congress was ostensibly setting this limit to promote the progress of science and useful arts. this was one of the arguments that prevailed in the "eldred v. ashcroft" case, when the supreme court upheld the constitutionality of the ctea. it is also pointed out by proponents that the extension did not prevent all works from going in the public domain. they note that the 1976 copyright act established that unpublished works created before 1978 would still begin entering the public domain january 1, 2003 (known author: life of the author plus 70 years; anonymous/pseudoanonymous/unknown author/works-for-hire: 120 years from creation), and that the provision remained unaffected by the 1998 extension. they also claim that congress has actually increased the scope of the public domain since, for the first time, unpublished works will enter the public domain.