The Copyright Clause of the U.S. Constitution (Article I, Section 8, Clause 8) gives Congress the power to "promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."
Note the words "Authors and Inventors." According to the plain language of our founding document--the very thing that conservatives are sworn to defend--intellectual property rights belonged to the creators, and only to the creators.
And, if the creator allows his or her rights to expire, they've expired. They're gone. Except if you're the current U.S. Supreme court, and you have a choice between upholding the plain language and giving your financial supporters a chance to make money without working for it.
Sadly, I think we all know what that choice is going to be. It will be one that does nothing for the artists of yesterday, and stands in the way of promoting the artists of tomorrow.