Bottom-Up Challenges to National Democracy: Mexico's (Legal) Subnational Authoritarian Enclaves.

How have Mexico's community-based democratic institutions, known as Usosy Costumbres (UyC) or Uses and Customs systems, affected local and national politics? Although informal UyC practices exist throughout Mexico, the state of Oaxaca formally changed its electoral codes in 1995 to legalize UyC. Statistical analysis of national election results shows that Oaxacan municipalities that formally adopted UyC systems thereafter experienced higher first-place party margins and higher levels of abstention compared to non-UyC systems. That these systems helped local leaders engineer election outcomes while reducing participation, even in national elections, undermines arguments about their democratic benefits. UyC rules appear to help preserve local authoritarian enclaves, with negative consequences for national democracy. [ABSTRACT FROM AUTHOR]