Mizrahi’s theoretical and empirical analysis of the electoral success of PAN is situated within a larger assessment of political parties and the changes they undergo. Her discussion of how and why political parties adjust to changes in the political landscape is particularly relevant to scholars of Latin America. Mizrahi contends that PAN party leaders have not acted quickly or decisively enough in making internal changes that will allow them to make a smooth transition from a survivalist minority party to Mexico’s ruling party. In contrast to the past, when the PAN’s main problems were associated with its inefficacy in the electoral arena, today the party confronts problems associated with its electoral success. Mizrahi argues that PAN’s relatively unchanged party structure presents serious obstacles to electoral expansion. Mizrahi’s account is analytically powerful and offers clear policy and political suggestions for her subject itself. This definitive work will be welcomed by political scientists, policy makers, and scholars of Latin America.