The Overton window is a concept in political theory, named after the former vice president of the Mackinac Center for Public Policy, Joe Overton, who developed the model. It describes a "window" in the range of public reactions to ideas in public discourse, in a spectrum of all possible options on an issue. Overton described a method for moving that window, thereby including previously excluded ideas, while excluding previously acceptable ideas. The technique relies on people promoting ideas even less acceptable than the previous "outer fringe" ideas. That makes those old fringe ideas look less extreme, and thereby acceptable. Delivering rhetoric to define the window provides a plan of action to make more acceptable to the public some ideas by priming them with other ideas allowed to remain unacceptable, but which make the real target ideas seem more acceptable by comparison.

The degrees of acceptance of public ideas can be described roughly as:

• Unthinkable
• Radical
• Acceptable
• Sensible
• Popular
• Policy

The Overton Window is a means of visualizing which ideas define that range of acceptance by where they fall in it, and adding new ideas that can push the old ideas towards acceptance merely by making the limits more extreme

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