The question of how partisanship is influenced by exogenous factors has been vigorously debated, yet this debate is less frequently noted in the literature on Latino partisanship. This study analyzes the 2006 Latino National Survey with geographic identifiers to explore how the political context of a county influences Latino partisan self-identification. There are a variety of reasons why the political environment might influence Latinos’ partisan choice. First, a substantial proportion of the adult Latino population in the United States is foreign-born, potentially lessening the influence of parental partisan socialization. Second, increased migration to areas outside the Southwest has exposed Latinos to new and different social, political, and economic environments. Using subgroup analysis, interactive logit models, and regression discontinuity, we find that the local political context influences the party attachment of Latino immigrants in predictable ways. However, for Latinos born in the United States, our analysis does not provide evidence of a causal connection between partisan environment and an individual's partisan identification.