The Overton window, also known as the window of discourse, is the range of ideas tolerated in public discourse. The term is derived from its originator, Joseph P. Overton, 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.
Political commentator Joshua Treviño postulated that the 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.
The alt-right—the umbrella term for online groups and people who espouse white supremacy, white nationalism, misogyny, and other forms of bigotry—isn’t a political movement in the conventional sense, says Andrew Marantz, who covers media and politics for The New Yorker. The alt-right doesn’t intend to win a majority in Congress, at least not right away. The goal, rather, is to change how America thinks. Ideologues in the movement refer to shifting the “Overton window,” a sociological concept that defines which ideas are speakable in public at any given time. Marantz explains to David Remnick exactly how ideas and memes are being moved from the fringes of the far right to the center of American discourse.