Theoretical Foundations and Immigrant Partisan Development in The United States

Author

• Atinuke Elizabeth Ayowole-Muili, Southern Illinois University CarbondaleFollow

Date of Award

5-1-2026

Degree Name

Doctor of Philosophy

Department

Political Science

First Advisor

Mulligan, Kenneth

Abstract

This dissertation develops Temporal Exposure Theory to explain how immigrants in the United States acquire and strengthen partisan identity. Whereas traditional political socialization theory emphasizes adolescence as the critical period of partisan formation, this study argues that for immigrants, partisanship emerges cumulatively through prolonged exposure to the U.S. political environment. Using nationally representative data from the 2020 American National Election Study and the 2021 Pew American Trends Panel, I employ ordered probit models, mediation analysis, and robustness checks across different functional form of time. Results show that partisan strength increases with time in the U.S., accelerating after about two decades of residence and converging toward levels observed among the native-born. This temporal process indirectly fuels affective polarization by strengthening partisan attachments. Religion emerges as a significant predictor of partisan strength in the baseline models, while income is only marginally influential, and age-at-arrival exerts no independent effect. These findings advance political behavior scholarship by reframing immigrant incorporation as a temporally contingent, nonlinear process. This dissertation contributes to knowledge by (1) testing the applicability of political socialization theory to immigrants, (2) demonstrating the robustness of temporal exposure across alternative measures, (3) clarifying the limited role of age and age at arrival. Together, the study demonstrates that immigrants’ partisan development is best understood as a cumulative adaptation shaped by time, rather than as simply different from native-born trajectories.