Examining the Bonding Effects of Party: A Comparative Analysis of Roll-Call Voting in the U.S. and Confederate Houses

Abstract

This paper examines whether political parties influence Congressional roll-call voting. Rather than focusing on contemporary evidence, my approach is historical: analyzing voting behavior in the U.S. and Confederate Houses during the Civil War. The U.S. and Confederate cases provide a unique opportunity for a comparative analysis because the two legislative systems were nearly identical in all facets, except that a strong two-party system was in place in the U.S. while a party system did not exist in the Confederacy. Thus, using vote-scaling techniques developed by Poole and Rosenthal (1985, 1991, 1997), I examine how roll-call voting in a party system (the U.S. House) differs from roll-call voting in a similar nonparty system (the Confederate House). My results indicate that voting in the U.S. House was considerably more predictable than voting in the Confederate House. Moreover, from additional tests, I conclude that these voting differences were due not to differences in the structure of preferences, but rather to the existence (or nonexistence) of political parties. In the U.S. House, party had a significant, independent effect on vote choice, after controlling for members' personal preferences. No such effect existed in the party-less Confederate House.