Environmental issue linkage as an electoral advantage::the case of NAFTA

Why would some legislators alter their votes on trade agreements in return for environmental side agreements that may be hard to enforce? While numerous studies have examined the effects of side agreements, few have evaluated their impact on legislators’ positions on a trade agreement over time. This paper examines the effects of the environmental side deal attached to NAFTA, with novel time-series survey data that captures the evolution of House members’ positions on NAFTA during discussion and finalization of the environmental side of the free trade agreement. I find that pro-environmental legislators in safe districts tended to withdraw their support for NAFTA once the side deal was agreed upon, whereas those in competitive districts stood their ground and increased their support in the final stage of voting. Contrary to the conventional wisdom, I find little evidence that the side deal assuaged legislators in import-competing districts. This article shows how the effectiveness of international institutions is moderated in important ways by electoral considerations.