Gubernatorial Coattails in Mexican Congressional Elections

Mexican congressional elections 1979-2009 are examined to determine if gubernatorial candidates have coattails helping candidates on the same ticket get elected to higher office and how the advent of democracy changed this. Analysis distinguishes rates at which gubernatorial votes transfer to congressional races from vote thresholds that gubernatorial candidates must exceed to help, rather than hinder, copartisans. Regression estimates reveal that state parties transferred, on average, 49% of their gubernatorial success to congressional candidates in a concurrent race since 1979 and 69% since 1997. Thresholds indicate that it is easier for the PAN and the left to gain from coattails than the PRI, but the difference shrunk with democracy. Presidential coattails, examined for reference, are shorter on average than gubernatorial ones. So local forces appear to move Mexican congressional campaigns and elections as much as national forces since at least 1979, raising questions about the relevance of federalism in developing nations.