Political polarization, congressional redistricting, and trade liberalization

During the last 50 years, political polarization in the US House of Representatives has intensified. One explanation for this trend emphasizes the importance of congressional redistricting. This paper analyzes the relationship between political polarization and redistricting in the context of two trade liberalization bills. The results of the paper indicate that redistricting has not contributed significantly to party polarization over trade policy although it has produced a partisan shift in favor of trade liberalization. Redistricting does not appear to impact political polarization largely because district-level characteristics currently are dominated by broader, national factors such as party affiliation. The results of the paper clearly demonstrate this point by showing that changes in party affiliation have a much greater impact on voting behavior than changes in district characteristics. The paper also finds, however, that institutional control of the redistricting process at the state level has influenced political polarization with respect to trade policy.