The political sociology of elections in Mexico is virtually unexplored territory, and the use of public opinion polls to identify preferences and trends is in the earliest stages of development and thus is viewed with some skepticism. This chapter attempts to test the usefulness and reliability of opinion polls in Mexico. It presents the analysis of some surveys conducted by the author and explains the predictions that were made of electoral behavior in the July 1985 elections. An analysis of the July 1985 elections can help to produce a clearer picture of the strength or weakness of the system and of the possibilities— or lack of feasibility—of political practices and parties. The July 1985 elections were, unquestionably, an occasion for Mexican and foreign intellectuals and politicians to update their interpretations about Mexico's future. In this context, the interest in opinion polls as elections drew near may be considered a first step forward.