[Declanomous]

This seems like a really important distinction. Though, the fact that other works can be copyrighted seems like that distinction isn't that important.

Also, doesn't the US have international agreements regulating copyright, and couldn't those protections be much more broad than the constitutional protections anyways?

[wildmusings]

There is no right to copyright; in fact Congress could abolish copyrights altogether tomorrow if it wished. Rather, there is an enumerated power for Congress to create copyright. If one could prove that a certain aspect or application of copyright law falls outside of that enumerated power, then it would be void as Congress had no power to create it in the first place.

[projektfu]

If it weren't specified in the US Constitution then it would devolve to common law and State constitutions because of the elastic clause. The right of copyright was invented before the US Constitution.