Overton window


The Overton window is the range of subjects and arguments politically acceptable to the mainstream population at a given time. It is also known as the window of discourse. The key to the concept is that the window changes over time; it can shift, or shrink or expand. It exemplifies "the slow evolution of societal values and norms".
The term is named after the American policy analyst and former senior vice president at Mackinac Center for Public Policy, Joseph Overton, who proposed that the political viability of an idea depends mainly on whether it falls within an acceptability range, rather than on the individual preferences of politicians using the term or concept. According to Overton, the window frames the range of policies that a politician may recommend without appearing too extreme, in order to gain or keep public office given the climate of public opinion at that particular time.

Summary

In the early 1990s, Overton described a spectrum from "more free" to "less free" with regard to governmental intervention, which he presented graphically on a vertical axis to avoid comparison with the left-right political spectrum. As the spectrum moves or expands, an idea at a given location on the scale may become more or less politically acceptable. Overton claimed that politicians typically act freely only within the "window" of those seen as acceptable. After his death, his Mackinac Center for Public Policy colleague, Joseph Lehman, further developed the idea and named it after him.
According to Lehman:
He presented the concept as simply a description of how ideas operate in public discourse, and not about advocacy of extreme policy proposals. In an interview with The New York Times, he said:
The political commentator Joshua Treviño has postulated six degrees of acceptance of public ideas: "roughly"
  • unthinkable
  • radical
  • acceptable
  • sensible
  • popular
  • policy
On this basis, the Overton window comprises the politically possible ideas: those in the lower part of the list, from acceptable downward. Proponents of policies outside the window may then seek to expand the window, by highlighting their own proposals or others similar to them, or to shift the window by devaluing opposed ideas. Proponents of current policies, or similar ones within the window, might attempt to narrow the window by convincing people that policies outside the status quo should be deemed unacceptable.
Treviño emphasised that while this analysis originated on the political Right, and is mainly in use there, it is equally available to think tanks on the Left.
The concept of a shifting range of acceptability has been applied in areas unrelated to political policy, as far afield as neonatology.