Joe shared his abstract concept with me in the mid-1990s. He observed that any collection of public policies within a policy area, such as education, can be arranged in order from more free to less free (or from less government intervention to more). To avoid comparison with the left-right political spectrum, he arranged the policies from bottom (less free) to top (more free).
At any one time, some group of adjacent policies along the freedom spectrum fall into a "window of political possibility." Policies inside the window are politically acceptable, meaning officeholders believe they can support the policies and survive the next election. Policies outside the window, either higher or lower, are politically unacceptable at the moment. If you shift the position or size of the window, you change what is politically possible.
Click here to learn more about this model of policy change, and use the interactive gadget to conceptualize what's politically possible. Where do you think we are today in Oklahoma with regard to educational freedom? One thing's for sure, we're further along today than we were last month.