Moonbat
Moonbat is a political epithet coined in 2002 by Perry de Havilland of "Samizdata," a libertarian weblog. It was originally a play on the last name of George Monbiot, a columnist for The Guardian and was originally rendered as 'Barking Moonbat'. The term also evokes the traditional association between the moon and insanity. It now enjoys great currency in the conservative and libertarian blogosphere as an all-purpose insult for modern liberals (in the American sense of the word), war protestors, and other ideological opponents. It is similar to the epithet Idiotarian and like that term can also be applied to people anywhere on the political spectrum (for example both terms have also been used to describe US conservative Pat Buchanan).
According to de Havilland, a moonbat is "someone on the extreme edge of whatever their -ism happens to be." Adriana Cronin defines the term as "someone who sacrifices sanity for the sake of consistency." This term has long been used to describe protesters on the political Left, but was originally coined to also describe commentators on the political Right as well as certain libertarians.
Moonbat was frequently used to describe those of any political persuasion who believe in conspiracy theories. Examples include those who believe that the terrorist attacks of 9/11 were engineered by George W. Bush, or that the US invaded Iraq to drive up oil prices or under the directions of Israel.
Lately the term has come into wider use appearing in political cartoons, political forums, and web-logs. In some instances 'Moonbat' is used, quite incorrectly, to classify anyone who disagrees with the Bush White House. The term was also used in a cartoon by Dan Perkins in the early part of December 2005.