Overton Window
The range of political ideas considered acceptable for mainstream discussion at a given moment. Named for Joseph Overton of the Mackinac Center for Public Policy, the concept describes how the boundaries of acceptable discourse can be deliberately shifted: by repeatedly introducing ideas previously considered extreme, advocates can normalize those ideas over time until they enter the acceptable range. Both ends of the political spectrum use the technique. Think tanks, front groups, and partisan media are the primary infrastructure by which the window gets moved.