An Introduction to the Overton Window of Political Possibilities

Editor's Note: The concept of the Overton Window was first developed in the mid-1990s by Joe Overton of the Mackinac Center for Public Policy, and it was discussed regularly at Mackinac Center seminars. For a brief explanation of the concept, an interactive tool and answers to common questions about the Window and the Mackinac Center, go to or click here. The essay below is the earliest published Mackinac Center article on the Overton Window for a general audience.

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(Prefatory Note: The late, esteemed Joseph P. Overton exerted enormous influence from 1992 to 2003 as a researcher, author and the Mackinac Center for Public Policy’s senior vice president. Key his name into this Web site’s search engine and you’ll see nearly endless references to his work. He was killed in a plane crash on June 30, 2003 but continues to be a source of inspiration to the many around the world who knew him. He would be 46 years of age today — Jan. 4, 2006. On this day we are pleased to publish this essay by Nathan Russell as a further tribute to Joe and his legacy. — Lawrence W. Reed, President)

What does a think tank do? Does it educate? Advocate policy? Should a think tank focus on short-term or long-term goals?

Among Joe Overton’s many contributions, he was instrumental in defining the role of the Mackinac Center in particular and think tanks in general. He understood that, regardless of how persuasive the think tank, lawmakers are constrained by the political climate. Therefore, Overton concluded, to be truly successful, the Mackinac Center should not focus on direct policy advocacy, but instead should focus on educating lawmakers and the public in an attempt to change the political climate.

To answer the inevitable questions about the role of a think tank, Overton developed an explanation that others have since dubbed the "Overton Window of Political Possibilities." Though his theory has roots in complex public choice economics, it boils down quite easily.[1]

Imagine, if you will, a yardstick standing on end. On either end are the extreme policy actions for any political issue. Between the ends lie all gradations of policy from one extreme to the other. The yardstick represents the full political spectrum for a particular issue. The essence of the Overton window is that only a portion of this policy spectrum is within the realm of the politically possible at any time. Regardless of how vigorously a think tank or other group may campaign, only policy initiatives within this window of the politically possible will meet with success. Why is this?

Politicians are constrained by ideas, even if they have no interest in them personally. What they can accomplish, the legislation they can sponsor and support while still achieving political success (i.e. winning reelection or leaving the party strong for their successor), is framed by the set of ideas held by their constituents — the way people think. Politicians have the flexibility to make up their own minds, but negative consequences await the elected officeholder who strays too far. A politician’s success or failure stems from how well they understand and amplify the ideas and ideals held by those who elected them.

In addition to being dependent on the ideas that form the boundaries of the political climate, politicians are also known to be self-interested and desirous of obtaining the best political result for themselves.[2] Therefore, they will almost always constrain themselves to taking actions within the "window" of ideas approved of by the electorate. Actions outside of this window, while theoretically possible, and maybe more optimal in terms of sound policy, are politically unsuccessful. Even if a few legislators were willing to stick out their necks for an action outside the window, most would not risk the disfavor of their constituents. They may seek the good of those who elected them, and even the good of the state or nation as a whole, but in pursuing the course they think is best, most will certainly take into account their political future. This is the heart of the Overton window theory.

So, if a think tank’s research and the principles of sound policy suggest a particular idea that lies outside the Overton window, what is to be done? Shift the window. Since commonly held ideas, attitudes and presumptions frame what is politically possible and create the "window," a change in the opinions held by politicians and the people in general will shift it. Move the window of what is politically possible and those policies previously impractical can become the next great popular and legislative rage.

Likewise, policies that were once acceptable become politically infeasible as the window shifts away from them. Think tanks can shape public opinion and shift the Overton window by educating legislators and the public about sound policy, by creating a vision for how things could be done, by conducting research and presenting facts, and by involving people in the exchange of ideas.

The example Joe Overton often used to illustrate his window theory was the Michigan school choice issue during the 1980s and ‘90s. The political spectrum for education ranges from full parental choice on the high end to a complete government monopoly without private schools, home schooling, charter schools or any other school choice on the low end. On this spectrum the politically possible range of options was very limited during the 1980s. Politicians could advocate minor, incremental changes for home schooling, and private schools were part of the status quo, but charter schools were definitely out of bounds for a politician to seriously contemplate.

As citizens became aware of education options and their success in other places, the political climate became more favorable and the window of political possibilities in Michigan began to expand to where politicians could advocate home schooling, school choice and even charter schools without losing at the polls. Not only was the upper limit of the window expanded, but the lower boundary has also moved upwards as well — making it politically unwise to push for restrictions on the education freedoms that have been gained.

Home schooling is here to stay, charter schools are well established, and school choice continues to gain ground. In fact, in some parts of Michigan it is now even possible to run for office on a platform that includes the Universal Tuition Tax Credit — another Overton innovation — a situation that was unthinkable just 10 years ago.

Perhaps the Overton window theory is best summed up by a quote from Milton Friedman in his preface to the 1982 edition of Capitalism and Freedom: "That, I believe, is our basic function: to develop alternatives to existing policies, to keep them alive and available until the politically impossible becomes politically inevitable."

A long-term focus on shifting the Overton window allows a think tank to follow its ideals and perform a genuinely positive public service, instead of being constrained to merely advocating those policies that are currently possible. When the window of political possibilities is moved along the political spectrum, the impossible becomes desirable and the simply desirable becomes imperative. This is the true influence of a think tank — shaping the political climate of future legislative and legal debates by researching, educating, involving and inspiring.


Nathan J. Russell, a 2004 graduate of Hillsdale College, is a graduate student in the Ph.D. program in Economics at George Mason University in Fairfax, Virginia. In 2004 and 2005, Russell served as a summer intern at the Mackinac Center for Public Policy, a research and educational institute headquartered in Midland, Mich. Permission to reprint in whole or in part is hereby granted, provided that the author and the Center are properly cited.


[1] For a more thorough economic or historical treatment, please see Gordon Tullock’s Politics of Persuasion (1967).

[2] Basic public choice theory, developed by James Buchanan and Gordon Tullock in their 1962 book, The Calculus of Consent, explores the consequences of realizing that politicians are just like us — and therefore are subject to the same motives, weaknesses, desires, and self-interests.