Extreme polarization in American politics—and especially in the U.S. Congress—is perhaps the most confounding political phenomenon of our time. This book binds together polarization in Congress and polarization in the electorate within an ever-expanding feedback loop. This loop is powered by the discipline exerted by the respective political parties on their Congressional members and district candidates and endorsed by the voters in each Congressional district who must choose between the alternatives offered. These alternatives are just as extreme in competitive as in lop-sided districts. Tight national party discipline produces party delegations in Congress that are widely separated from one another but each ideologically narrowly distributed. As district constituencies become more polarized and are egged on by activists, parties are further motivated to move past a threshold and appeal to their respective bases rather than to voters in the ideological center. America has indeed acquired parties with clear platforms—once thought to be a desirable goal—but these parties are now feuding camps. What resolution might there be? Just as the progressive movement slowly replaced the Gilded Age, might a new reform effort replace the current squabble? Or could an asymmetry develop in the partisan constraints that would lead to ascendancy of the center, or might a new and over-riding issue generate a cross-cutting dimension, opening the door to a new politics? Only the future will tell.

This book integrates spatial and behavioral perspectives - in a word, those of the Rochester and Michigan schools - into a unified theory of voter choice and party strategy. The theory encompasses both policy and non-policy factors, effects of turnout, voter discounting of party promises, expectations of coalition governments, and party motivations based on policy as well as office. Optimal (Nash equilibrium) strategies are determined for alternative models for presidential elections in the US and France, and for parliamentary elections in Britain and Norway. These polities cover a wide range of electoral rules, number of major parties, and governmental structures. The analyses suggest that the more competitive parties generally take policy positions that come close to maximizing their electoral support, and that these vote-maximizing positions correlate strongly with the mean policy positions of their supporters.

Professors Merrill and Grofman develop a unified model that incorporates voter motivations and assesses its empirical predictions--for both voter choice and candidate strategy--in the United States, Norway, and France. The analyses show that a combination of proximity, direction, discounting, and party ID are compatible with the mildly but not extremely divergent policies that are characteristic of many two-party and multiparty electorates. All of these motivations are necessary to understand the linkage between candidate issue positions and voter preferences.

This book integrates spatial and behavioral perspectives - in a word, those of the Rochester and Michigan schools - into a unified theory of voter choice and party strategy. The theory encompasses both policy and non-policy factors, effects of turnout, voter discounting of party promises, expectations of coalition governments, and party motivations based on policy as well as office. Optimal (Nash equilibrium) strategies are determined for alternative models for presidential elections in the US and France, and for parliamentary elections in Britain and Norway. These polities cover a wide range of electoral rules, number of major parties, and governmental structures. The analyses suggest that the more competitive parties generally take policy positions that come close to maximizing their electoral support, and that these vote-maximizing positions correlate strongly with the mean policy positions of their supporters.

Professors Merrill and Grofman develop a unified model that incorporates voter motivations and assesses its empirical predictions--for both voter choice and candidate strategy--in the United States, Norway, and France. The analyses show that a combination of proximity, direction, discounting, and party ID are compatible with the mildly but not extremely divergent policies that are characteristic of many two-party and multiparty electorates. All of these motivations are necessary to understand the linkage between candidate issue positions and voter preferences.