According to a 2006 article by New York Times self-described "language maven" William Safire, the term was first used by science fiction author Robert A. Heinlein in 1947. Heinlein used the term in a 1947 short story, "Space Jockey", as the name of a rocket spacecraft used for the third step of a journey from the Earth to the Moon. Descriptions of bat-like people on the Moon were part of the 1835 Great Moon Hoax.
A long poem, The Proving of Gennad: A Mythological Romance by Landred Lewis (1890), uses the term "moonbat" to refer to unsound ideas, but not specifically political ones.
Examples of usage 
- On March 14, 2000 Jonah Goldberg's National Review Online column "Our, *ahem*, FAQ Welcome New Readers" contained the following: "Alas, because Goldberg watches Baywatch everyday and can name the main characters in almost every Marvel comic book from 1976 to 1986, he occasionally makes errors. Far more often, he simply writes things that make readers say, 'Is this guy higher than a moonbat?'"
- Howie Carr has used the term a number of times in his column in the Boston Herald. The earliest known use by Carr was in a Rocky Mountain News article on August 8, 1996. At the time, the Japanese clothing brand "MoonBat" was the sponsor of an annual 64 day California – New Jersey ultramarathon foot race, called the "MoonBat Transcontinental Footrace". In 2008, Carr wrote about the number of "Moonbats" inhabiting the town of Arlington, Massachusetts. In response, a group of Arlington residents founded the Menotomy Moonbats to raise money for their local public schools: Menotomy was the historical name for Arlington during the American Revolutionary War.
- Margery Eagan, another Herald columnist, used the term several times in 2006 and 2007 to characterize some supporters of Democratic governor Deval Patrick.
- Conservative columnist and blogger Michelle Malkin was quoted in March 2006 by Howard Kurtz as writing, "But now the determined moonbat hordes have exposed multiple instances of what clearly appear to me to be blatant lifting of entire, unique passages by [conservative blogger] Ben Domenech from other writers," in reference to Domenech's resignation from the Washington Post after evidence of his plagiarism came to light.
- In September 2006, William Safire said that "The prevailing put-down of right-wing bloggers is wingnuts; this has recently been countered by the vilification of left-wing partisans who use the Web as moonbats..."
- The term is also often used in the UK to refer to George Monbiot, owning to its similarity with his surname, and referring to his left-wing views.
- Science fiction author Tom Kratman, in his Desert Called Peace series, portrays masses of genetically engineered, cowardly, bat-winged reptiles, with septic mouths, which feast on the eyes and brains of the young, the weak, the sick, and the feeble minded, and which have a nocturnal cry: "mnnnbt...mnnnbt...mnnnbt." The reptiles are called, "antaniae," because the planet has a moon named, "Hecate," and Antania was the manfestation of Hecate as "Enemy of Mankind." Taken together with the bat-like wings, they are, again, "Moonbats," for that planet.
See also 
- Safire, William (2006-09-03). "On Language: Moon Bats & Wing Nuts". The New York Times Magazine. Retrieved 2008-04-02.
- Jonah Goldberg. Our, *ahem*, FAQ, National Review Online
- Carr, Howie (2007-01-31). "Kerry's continued mincing just proves he's not so Swift". Boston Herald. p. 10.
- Carr, Howie (2007-02-25). "Draped in controversy, is it curtains for Deval?". Boston Herald. p. 9.
- Carr, Howie (2007-03-08). "Hillary circling as Obama looks for parking spot". Boston Herald. p. 4.
- Carr, Howie (2007-03-14). "Good luck, Lefty - it's going to be a long haul". Boston Herald. p. 4.
- Carr, Howie (2007-03-23). "Pols paying higher taxes, show yourselves". Boston Herald. p. 16.
- Carr, Howie (2007-04-22). "Aging moonbats tapped to `advise' governor". Boston Herald. p. 10.
- Carr, Howie (1996-08-08). "Rep Collins Loses Dem Primary". Rocky Mountain News. (via Highbeam Research archive)
- "Ultramarathon; 2,926 Miles In 517 Hours Wins Race". The New York Times. August 21, 1994.
- Carr, Howie (2008-07-03). "Marzilli-loving Moonbats have their blinders on". Boston Herald. Retrieved 2008-08-22.
- Carr, Howie (2008-08-03). "Test: How to tell if you’re a moonbat". Boston Herald. Retrieved 2008-08-22.
- Menotomy Moonbats volunteer web site
- Chabot, Hillary (2008-08-02). "Moonbats unite! Show pride in hotbed suburb". Boston Herald. Retrieved 2008-08-22.
- Metzger, Andy (2008-07-31). "Political tees". Arlington Advocate Newspaper. Retrieved 2008-08-22.
- Eagan, Margery (2006-09-21). "Moonbats swarming in Mass". Boston Herald. Retrieved 2007-03-18.
- Eagan, Margery (2006-09-24). "Battle For Governor: Sunday Smackdown". Boston Herald. Retrieved 2007-03-18.
- Eagan, Margery (2007-03-08). "Moonbats enter their blue phase". Boston Herald. Retrieved 2007-03-17.[dead link]
- Kurtz, Howard (2006-03-25). "Post.com Blogger Quits Amid Furor". The Washington Post. pp. C01. Retrieved 2007-07-03.