The person who wrote "The Endarkenment" is Jeff McDaniel. For Mr. McDaniel's notes about who the real chancellors of American poetry are, see http://poetry.about.com/library/weekly/aa100902a.htm
His books are The Splinter Factory, Alibi Factory, and The Forgiveness Parade. As a service to my readers, I searched the table of contents of each of these books, but no poem called "The Endarkenment." However, this term is apparently widely used, so many people must have thought themselves extremely clever as they separately coined it. Including Jeff McDaniel.
Other random note, for anyone who rejoiced to hear I had an umbrella: because I bought the traditional, non-collapsible type of umbrella, I had ot leave it in Vancouver. Hence, though it rains today in SLC, I am without an umbrella. Tout ca change, tout c'est le meme chose.