So you can imagine my surprise when I'm reading an wikipedia article on Grover Cleveland, and it turns out that Mugwumps were a group of Republican activists who supported Cleveland (the Democratic candidate) in the 1884 presidential election. According to Wikipedia:
Dictionaries report "mugguomp" was an Algonquian word meaning "person of importance" or "war leader." Charles Anderson Dana, the colorful newspaperman and editor of the now-defunct New York Sun, is said to have given the Mugwumps their political moniker. Dana made the term plural and derided them as amateurs and public moralists.
During the 1884 campaign, they were often portrayed as "fence-sitters," with part of their body on the side of the Democrats and the other on the side of the Republicans. (Their "mug" on one side of the fence, and their "wump" on the other.)
Even stranger, apparently "Neo-Mugwump" is apparently another term for RINO: Republican In Name Only. Meaning, we almost elected a Neo-Mugwump for president in 2008. ;)
I don't know what to say, given that one of the wierdest images in my life is apparently a Republican movement...
It's like discovering that chocolate has one of the higher concentrations of lead among foods us Westerners typically eat.