ECONOMIC INTERESTS, PARTISAN POLITICS, AND ENVIRONMENTAL POLARIZATION

Abstract

Focusing on environmental legislation since 1970s, this paper studies the mechanisms behind party polarization in the US Congress. Two questions guide the analysis. First, why, and how did environmental polarization emerge from initial bipartisanship? Second, why did Republicans become anti-environmental and Democrats pro-environmental? The theoretical framework extends stochastic electoral competition models by incorporating new interest groups into political parties. The model generates a link between the initial composition of the parties, the behavior of new interest groups and the pattern and level of polarization along the new policy dimension (e.g., environment). Our empirical analysis uses data on congressional environmental votes from 1971 to 2016, on legislator characteristics, congressional district economic and demographic information, and interest group contributions. The empirical evidence confirms that party polarization emerged over time from initial bipartisanship and suggests that the connection between parties and special interest groups played a crucial role.