It’s difficult because the most recent extensions were put in place to synchronize US copyright with the absurd durations pioneered by Europe and the Berne Convention. In effect, the US has allowed international treaties to supersede the Constitution’s requirement that copyright last “for limited times.”
I think it went the other way around. Corrupt US industries first pushed those conventions and then pressured US legislature to "synchronize" with them. It's all a big pile of corrupt BS that tries to bypass normal lawmaking, so pushing back against it should be only natural.
I'm not familiar with the background here, so I just checked on Wikipedia. It says
"After the United States' accession to the Berne convention, a number of copyright owners successfully lobbied the U.S. Congress for another extension of the term of copyright, to provide for the same term of protection that exists in Europe."
(https://en.wikipedia.org/wiki/Copyright_Term_Extension_Act#:...)
This would seem to indicate that the parent was right -- the long extension to copyright is because the US decided to match Europe's protections. Although, on second reading of your comment, I wonder if you mean that US companies convinced Europe to provide longer protections, with the intent to then make the US match the policies they pushed in Europe? That seems very elaborate
Reading more of the Wikipedia link, while it is true that:
> The Senate Report gave the official reasons for passing copyright extension laws [...] to ensure adequate copyright protection for American works in foreign nations
... it also notes:
> The report also included minority opinions by Herb Kohl and Hank Brown, who believed that the term extensions were a financial windfall to current owners of copyrighted material at the expense of the public's use of the material.
And who supported the bill and lobbied for it?
> Since 1990, The Walt Disney Company had lobbied for copyright extension. The legislation delayed the entry into the public domain of the earliest Mickey Mouse cartoons, leading detractors to the nickname "The Mickey Mouse Protection Act".
> In addition to Disney, California congresswoman Mary Bono (Sonny Bono's widow and Congressional successor), and the estate of composer George Gershwin supported the act. Mary Bono, speaking on the floor of the United States House of Representatives, said: "Actually, Sonny wanted the term of copyright protection to last forever. I am informed by staff that such a change would violate the Constitution. ... As you know, there is also [then-MPAA president] Jack Valenti's proposal for term to last forever less one day. Perhaps the Committee may look at that next Congress."
> Other parties that lobbied in favor of the Bono Act were Time Warner, Universal, Viacom, the major professional sports leagues (NFL, NBA, NHL, MLB), and the family of slain singer Selena Quintanilla-Pérez.
So, primarily American corporations and individuals looking for a "financial windfall", including Sonny Bono himself who would have liked the act to completely violate the US constitution and make copyright last forever.
What you don't see on this list are any European organisations asking the USA to match their own copyright durations.
