Representation in Congress provides a theory of dyadic policy representation intended to account for when belief sharing, delegate, responsible party, trustee, and 'party elite led' models of representational linkage arise on specific policy issues. The book also presents empirical tests of most of the fundamental predictions for when such alternative models appear, and it presents tests of novel implications of the theory about other aspects of legislative behavior. Some of the latter tests resolve contradictory findings in the relevant, existing literature - such as whether and how electoral marginality affects representation, whether roll call vote extremism affects the re-election of incumbents, and what in fact is the representational behavior of switched seat legislators. All of the empirical tests provide evidence for the theory. Indeed, the full set of empirical tests provides evidence for the causal effects anticipated by the theory and much of the causal process behind those effects.

This book develops a general explanation for party polarization in America from both historical and contemporary perspectives. Prior polarization studies focused exclusively on the modern era, but this work traces party polarization from the constitutional convention of 1787 to the present. Using such a broad historical perspective shows that what was unusual in American history was the period of low polarization from the Great Depression through 1980, rather than the period of high polarization of the modern era. Polarization is the norm of the American system, not the exception, and is likely to persist in the future. More theoretically, party polarization in America has been due to class-based conflict and rent-seeking by the patrician and plebian classes in various historical eras, rather than conflict over cultural values. As in earlier historical eras, modern party polarization has largely been elite-driven, with party entrepreneurs cunningly and strategically using polarization to their advantage.