njc wrote:That hinges on whether something which has been increased every time it should have expired is expected to continue to increase each such time. If the justices decide that Congress is doing an end run around the provision, they might well strike it down. When a judge at any level decides he's being gamed, he's likely to push back hard.
That does not reflect over history what has happened. The new law would cover those already covered by the old law in the same way a driver on the road has to obey a new traffic rule and not follow the old rule. Application of new law can work both ways to advantage or disadvantage a citizen in an existing situation. You suggest a situation that is phantasm: that, for example, Congress has every decade simply extended copyrights another decade.
apart from International and Digital-Age complications, Congress has acted to significantly change the law only five times since 1790, and four involving the sort of extensions you worry about..
1790
Extensive revisions - 1831 twenty-eight years with the possibility of a fourteen-year extension irrespective of the lifetime of the author, 1870 (administrative), 1891 (International provisions), 1909 twenty eight year extension, 1976, extended protection from life of the author plus fifty years , 1988 (International provisions), 1990 (Computer software), 1992 (automatic renewal), 1996 (computer provisions), 1998 (Bono Act, extended protection from life of the author plus fifty years to life of the author plus seventy years), 1998 (computer provisions), 2007 ("fair use"), 2010-present, courts busy with sorting out digital-age complications.