Dog-whistle politics is political messaging employing coded language that appears to mean one thing to the general population but has an additional, different or more specific resonance for a targeted subgroup. The phrase is often used as a pejorative because of the inherently deceptive nature of the practice and because the dog-whistle messages are frequently distasteful to the general populace. The analogy is to a dog whistle, whose high-frequency whistle is heard by dogs but inaudible to humans.
The term can be distinguished from "code words" used in some specialist professions, in that dog-whistling is specific to the political realm. The messaging referred to as the dog-whistle has an understandable meaning for a general audience, rather than being incomprehensible.
According to William Safire, the term "dog whistle" in reference to politics may have been derived from its use in the field of opinion polling. Safire quotes Richard Morin, director of polling for The Washington Post, as writing in 1988,
subtle changes in question-wording sometimes produce remarkably different results.... researchers call this the 'Dog Whistle Effect': Respondents hear something in the question that researchers do not
and speculates that campaign workers adapted the phrase from political pollsters.
In her 2006 book, Voting for Jesus: Christianity and Politics in Australia, academic Amanda Lohrey writes that the goal of the dog-whistle is to appeal to the greatest possible number of electors while alienating the smallest possible number. She uses as an example Australian politicians using broadly appealing words such as "family" and "values", which have extra resonance for Christians, while avoiding overt Christian moralizing that might be a turn-off for non-Christian voters.
Australian political theorist Robert E. Goodin argues that the problem with dog-whistling is that it undermines democracy, because if voters have different understandings of what they were supporting during a campaign, the fact that they were seeming to support the same thing is "democratically meaningless" and does not give the dog-whistler a policy mandate.
The term was first picked up in Australian politics in the mid-1990s, and was frequently applied to the political campaigning of John Howard. Throughout his 11 years as Australian prime minister and particularly in his fourth term, Howard was accused of communicating messages appealing to anxious and perhaps racist white Australian voters using code words such as "un-Australian", "mainstream" and "illegals".