Anyone who has been following my posts in the past few days will have surmised that Unequal Democracy is a rather pessimistic book. But I've saved the most pessimistic finding for last. It concerns the ramifications of economic inequality for the workings of our political system. While Americans have a good deal of tolerance for economic inequality, that tolerance is predicated on the "national myth" that we enjoy "full civic equality despite material differences," as Michael Kinsley once put it. Cynics may doubt that "full civic equality" is a reality - but even they should be dismayed by the extent of inequality in the contemporary American political system.

I have measured the responsiveness of U.S. senators to the views of constituents with different incomes - distinguishing people in the bottom, middle, and top thirds of the national income distribution. The results show that senators' roll call votes are moderately strongly related to the views of middle-class constituents, and somewhat more strongly related to the views of affluent constituents. (The relative weight of affluent constituents is noticeably stronger for Republican senators than for Democratic senators.) What is most striking, however, is that there is no evidence of any discernible responsiveness to the preferences of constituents in the bottom third of the income distribution. The views of tens of millions of people with nothing in common but their low incomes seem to be utterly ignored by their elected representatives. Insofar as they get what they want with respect to policy, it is only because their views happen to correspond with those of affluent and middle-class people - or, even more importantly, with the partisan and ideological impulses of the senators themselves.

One common reaction to these findings is, "Of course elected officials ignore poor people - they don't vote." However, the fact of the matter is that millions of them do vote, and they still get ignored. My analysis allowed for differences in responsiveness attributable to turnout, general levels of political attentiveness, and contact with elected officials and their staffs. I found that voters' views weigh no more heavily than non-voters views in influencing the choices made by their elected officials. Even after taking account of differences in responsiveness attributable to turnout, attentiveness, and contacting, most of the disparity in responsiveness to affluent and poor constituents remains.

This pattern of unresponsiveness to low-income constituents holds for both Democratic and Republican senators. It holds across the whole range of issues that come before Congress, including salient roll call votes on such issues as the minimum wage, domestic spending, and civil rights. It also holds for a variety of salient votes on abortion - an issue where specifically economic interests might be expected to have little traction.

My pessimistic findings are strikingly supported by the separate findings of my Princeton colleague Martin Gilens, who has analyzed almost 2,000 survey questions measuring Americans' preferences regarding a wide variety of national policy issues. For each issue, Gilens examined whether a policy change supported or opposed by various segments of the public was subsequently adopted. He found a strong statistical relationship between the views of affluent citizens and the subsequent course of public policy, but a much weaker relationship for less affluent citizens. When he limited his analysis to issues on which rich people and poor people had divergent preferences, he found that the well-off were vastly more likely to see their views reflected in subsequent policy changes. Gilens concluded that "influence over actual policy outcomes appears to be reserved almost exclusively for those at the top of the income distribution."

The eminent political scientist Robert Dahl once suggested that "a key characteristic of a democracy is the continued responsiveness of the government to the preferences of its citizens, considered as political equals." By that standard, contemporary America hardly seems to qualify. While cynics will not be surprised to hear that poor people are less than equal in our political system, even they should be shocked and disturbed by the strength of the empirical evidence suggesting that the views of millions of poor Americans are utterly ignored by their elected representatives. As Gilens put it, "representational biases of this magnitude call into question the very democratic character of our society."