The Overton window, also known as the window of discourse, is the range of ideas the public will accept. It is used by media pundits. The term is derived from its originator, Joseph P. Overton (1960–2003), a former vice president of the Mackinac Center for Public Policy, who in his description of his window claimed that an idea's political viability depends mainly on whether it falls within the window, rather than on politicians' individual preferences. According to Overton's description, his window includes a range of policies considered politically acceptable in the current climate of public opinion, which a politician can recommend without being considered too extreme to gain or keep public office.
Overton described a spectrum from "more free" to "less free" with regard to government intervention, oriented vertically on an axis. As the spectrum moves or expands, an idea at a given location may become more or less politically acceptable. His degrees of acceptance of public ideas are roughly:
The Overton window is an approach to identifying which ideas define the domain of acceptability within a democracy's possible governmental policies. Proponents of policies outside the window seek to persuade or educate the public in order to move and/or expand the window. Proponents of current policies, or similar ones, within the window seek to convince people that policies outside it should be deemed unacceptable.
After Overton's death, others have examined the concept of adjusting the window by the deliberate promotion of ideas outside of it, or "outer fringe" ideas, with the intention of making less fringe ideas acceptable by comparison. The "door-in-the-face" technique of persuasion is similar.
"Many who before regarded legislation on the subject as chimerical, will now fancy that it is only dangerous, or perhaps not more than difficult. And so in time it will come to be looked on as among the things possible, then among the things probable;–and so at last it will be ranged in the list of those few measures which the country requires as being absolutely needed. That is the way in which public opinion is made."
"It is no loss of time," said Phineas, "to have taken the first great step in making it."
"The first great step was taken long ago," said Mr. Monk,–"taken by men who were looked upon as revolutionary demagogues, almost as traitors, because they took it. But it is a great thing to take any step that leads us onwards."
In his "West India Emancipation" speech at Canandaigua, New York, in 1857, abolitionist leader Frederick Douglass described how public opinion limits the ability of those in power to act with impunity:
Find out just what any people will quietly submit to and you have found out the exact measure of injustice and wrong which will be imposed upon them, and these will continue till they are resisted with either words or blows, or with both. The limits of tyrants are prescribed by the endurance of those whom they oppress.
The idea is very similar to an earlier theory that came to be known as Hallin's spheres. In his 1986 book The Uncensored War, communication scholar Daniel C. Hallin posits three areas of media coverage into which a topic may fall. The areas are diagrammed as concentric circles called spheres. From innermost to outermost they are the Sphere of Consensus, the Sphere of Legitimate Controversy, and the Sphere of Deviance.
Hallin's theory is developed and applied primarily as a theory that explains varying levels of objectivity in media coverage, but it also accounts for the ongoing contest among media and other political actors about what counts as legitimate disagreement, potentially leading to changes in the boundaries between spheres. As one study that applies Hallin's theory explains, "the borders between the three spheres are dynamic, depending on the political climate and on the editorial line of the various media outlets."
In popular culture
Christopher Buckley's novel Boomsday applies the Overton window to the subject of Social Security reform in the United States. The technique used was to agitate for "voluntary transitioning", that is, suicide at a certain age in exchange for benefits, as a method of reducing the cost of Social Security. Ultimately, the stated goal was for a more modest result of reducing the burden that it was claimed was imposed on younger people for the costs of Social Security.
On a 2016 podcast episode of the Tim Ferriss show, guest Eric Weinstein referred to Trump's recent suggestion to temporarily ban all Muslims from entering the country as being outside the Overton Window. 
- Ambit claim
- Argument to moderation
- Diffusion of innovations
- Door-in-the-face technique
- Slippery slope
- Framing (social sciences)
- Creeping normality
- Opinion corridor
- Political suicide
- Spiral of silence
- Third rail of politics
- Cultural hegemony
- David Weigel (2015-04-14). "Marco Rubio:No Iran Deal Unless the Country Recognizes Israel". Bloomberg Politics. Retrieved 2015-07-11.
- Paul Krugman (2015-02-27). "The Closed Minds Problem". The New York Times. Retrieved 2015-07-11.
- NNDB "intelligence aggregator" Web site, "Joseph P. Overton"
- "Joseph Overton biography and article index". Mackinac. Retrieved 2013-08-30.
- Joseph Lehman. "A Brief Explanation of the Overton Window". Mackinac Center for Public Policy. Retrieved 7 July 2012.
- Daily Kos story, "Why the Right-Wing Gets It--and Why Dems Don't"
- Daily Kos diary, "Morning Feature: Crazy Like a Fox?"
- BlackPast.org website "(1857) Frederick Douglass, 'If There Is No Struggle, There Is No Progress'"
- Hallin, Daniel (1986). The Uncensored War: The Media and Vietnam. New York: Oxford University press. pp. 116–118. ISBN 978-0-19-503814-9.
- Figenschou, Tine Ustad; Beyer, Audun (October 2014). "The Limits of the Debate How the Oslo Terror Shook the Norwegian Immigration Debate". The International Journal of Press/Politics 19 (4): 435. doi:10.1177/1940161214542954.
- Glenn Beck Web site, Books, "The Overton Window"
- "Eric Weinstein on Challenging “Reality,” Working with Peter Thiel, and Destroying Education to Save It". Tim Ferris. 13 January 2016. Retrieved 2016-01-17.
- Pilgrim, Mark (23 August 2006). "W3C and the Overton window - includes a clear explanation". Dive into Mark. Archived from the original on 18 July 2011.
- Diagram of the Overton window as described by Joseph Overton