Party polarization, disappearing regions, and nationalized environmental politics: Evidence from US Congress

The intersection of environmental politics, regionalism, and Congressional policymaking is not well-examined by extant scholarship, so it is unclear to what extent regionalism within parties explains Congressional actions, particularly as it pertains to shifting partisan dynamics and focus on nationalized issues, such as climate change. The authors use data from the League of Conservation Voters to track voting behaviors among members of Congress from 1971 to 2022. Findings indicate that regional differences within parties did not emerge until the Reagan administration, but subsequently increased in significance, hitting their peak during the Obama administration. By the Trump administration, regionalism within parties began to dissipate as partisan voting practices converged on environmental issues.