more from Larry Bartels:
Democracy and the Policy Preferences of Wealthy Americans (2013)
Economics Still Matters to Poorer Voters (2008)
Economic Inequality and Political Representation (2005)
UPDATE: Tyler Cowen points to a study that concludes that the poor are no worse represented than the rich. (Of course he does.)
Brunner, et al simply find that the votes of the wealthy and the poor are not dissimilar. Could this be because the rich and the poor both enjoy the same narrow band of policy choices?