What are the consequences of democratization? How do they manifest themselv
es sub-nationally? An intracountry comparative analysis of legislative inst
itutional change in the Mexican states can explore these theoretical questi
ons. The analysis focuses on three states with relatively similar structura
l conditions but remarkably different patterns of political competition. Da
ta include an interrupted time series regression analysis, in-depth field r
esearch, and more than seventy interviews. As a result of growing electoral
competition, legislatures gain greater autonomy from executives, more reso
urces, greater internal decentralization, and higher levels of activity.