Ezra Klein directs us to Larry Bartels:
Ezra Klein: Political Science Abstract of the Day: Larry Bartels: Economic Inequality and Political Representation:
I examine the differential responsiveness of U.S. senators to the preferences of wealthy, middle-class, and poor constituents. My analysis includes broad summary measures of senators’ voting behavior as well as specific votes on the minimum wage, civil rights, government spending, and abortion. In almost every instance, senators appear to be considerably more responsive to the opinions of affluent constituents than to the opinions of middle-class constituents, while the opinions of constituents in the bottom third of the income distribution have no apparent statistical effect on their senators’ roll call votes. Disparities in representation are especially pronounced for Republican senators, who were more than twice as responsive as Democratic senators to the ideological views of affluent constituents. These income-based disparities in representation appear to be unrelated to disparities in turnout and political knowledge and only weakly related to disparities in the extent of constituents’ contact with senators and their staffs.
And Ezra Klein comments:
And it should go without saying that the more focused politicians are on the preferences of their affluent constituents, the more their legislation will entrench and augment inequality, further erasing the preferences of the poor and middle class from consideration. That said, I would like to remind people that in 2001, we had a terrorist attack, and there's a war going on, and everything is different now, and there's really no time for procedural niceties like listening to the bottom third of the country.