The American Political Science Association Task Force on Inequality and American Democracy is a good starting point. The APSA Task Force’s findings on political inequality can be found here. Specifically, you can find their report on-line, or you can look at the book version, which includes the three longer sections on citizen voice, government responsiveness, and patterns of public policy making. For criticisms of the Task Force in the form of comment and reply, see the PS: Political Science and Politics symposium on Inequality and Democracy.
Dubrow, Joshua K. “Statement on the Study of Political Inequality“
Notes on Winters and Page (2009) “Oligarchy in the U.S.?”
Dubrow, Joshua K. “Intersectionality and Political Inequality”
Some Notes on Measures of Political Inequality
Notes on Defining and Measuring Political Inequality
More Notes on Piven and Cloward’s Discussion on Power Resources
Classic Readings on Class and Voting
Political Inequality and the 2008 U.S. Presidential Election
