Polarized America: the dance of ideology and unequal riches

Abstract

The idea of America as politically polarized--that there is an unbridgeable divide between right and left, red and blue states--has become a cliche. What commentators miss, however, is that increasing polarization in recent decades has been closely accompanied by fundamental social and economic changes--most notably, a parallel rise in income inequality. In Polarized America, Nolan McCarty, Keith Poole, and Howard Rosenthal examine relationships of polarization, wealth disparity, immigration, and other forces, characterizing it as a dance of give and take and back and forth causality.Using NOMINATE (a quantitative procedure that, like interest group ratings, scores politicians on basis of their roll call voting records) to measure polarization in Congress and public opinion, census data and Federal Election Commission finance records to measure polarization among public, authors find that polarization and income inequality fell in tandem from 1913 to 1957 and rose together dramatically from 1977 on; they trace a parallel rise in immigration beginning in 1970s. They show that Republicans have moved right, away from redistributive policies that would reduce income inequality. Immigration, meanwhile, has facilitated move to right: non-citizens, a larger share of population and disproportionately poor, cannot vote; thus there is less political pressure from bottom for redistribution than there is from top against it. In the choreography of American politics inequality feeds directly into political polarization, and polarization in turn creates policies that further increase inequality.