From the late 1960s until recently, Santa Cruz, California was the most politically progressive medium-sized or large city in the United States. An unlikely confederation of socialist-feminists, social-welfare liberals, neighborhood activists, and environmentalists stopped every major development project they didn't like after 1969, and controlled the city council from 1981 through the beginning of the 21st century. Berkeley, Burlington, Madison, San Francisco, Santa Monica -- none of them had as progressive a government for as long.
Since most cities are usually controlled by real estate developers and their buddies, Santa Cruz is a good test case for comparing theories of urban power. Atypical cases are helpful in eliminating theories from consideration if they cannot explain the unexpected events.
That's why Richard Gendron and I wrote The Leftmost City: Power and Progressive Politics in Santa Cruz (Westview Press, 2009).