The overton window came out of the Mackinac center so they have a lot of info on the theory.
I just want to say that I personally knew Joe Overton and considered him a friend. He was absolutely a brilliant political analyst. I truly enjoyed my discussions with him. As a police officer being friendly with the mackinaw center may seem to be a conflict of sorts. However, I was raised free market and believe in the American system. He helped shape some of my views but my views were already on par with the Mackinaw Center.