I beg to differ, the Constitution clearly specifies why copyright should exist: "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."

How does retroactively adding copyright to public domain works in anyway "promote" it's already been accomplished. This the same argument that was used Eldred vs. Ashcroft where this argument also failed. It was a bad ruling then and it's a bad ruling now.

If we want to have this decided by the lawmakers then we should amend the Constitution to grant this power.