[Fabozz]

The story you're thinking of is "The Return of William Proxmire" by Larry Niven (an SF giant in his own right). First printed in What Might Have Been? Volume I: Alternate Empires (Gregory Benford & Martin H. Greenberg eds., Bantam Spectra, 1989). Also available in the Requiem anthology (Tor, 1992). Nominated for the 1990 Best Short Story Hugo.

[FreedomPoster]

>>Larry Niven (an SF giant in his own right).

I heartily recommend both Niven's work and the Niven & Pournelle collaborations. Both were friends of Heinlein. "The Mote in God's Eye" is a fabulous first contact novel.