This story is about democracy and why a limited (voting) franchise is better than an unrestricted one. It was first brought to my attention in Robert Heinlein’s book of essays Expanded Universe, and is quite hard to find, since it’s probably not as popular as some of Twain’s other stories. I found it online after being pointed to a different story by a different author. That is why the internets are so great.
The Curious Republic of Gondour by Mark Twain