He sensed that the liberal vision of America did not match what he saw around him and began to question. Then he began to read.
And he began to realize that liberals believed in
I began reading not only the economics of Thomas Sowell (our greatest contemporary philosopher) but Milton Friedman, Paul Johnson, and Shelby Steele, and a host of conservative writers, and found that I agreed with them: a free-market understanding of the world meshes more perfectly with my experience than that idealistic vision I called liberalism.
...a state where everything was magically wrong and must be immediately corrected at any cost; [while] the world in which I actually functioned day to day—was made up of people, most of whom were reasonably trying to maximize their comfort by getting along with each other (in the workplace, the marketplace, the jury room, on the freeway, even at the school-board meeting).And eventually he opened his eyes and realized that he had become..., a conservative.
Read the whole thing here.
Jonah Goldberg's take on Mamet's conversion and on his critics is worth reading. Check it out here.