This study examines how language hierarchies shape political citizenship and belonging through a comparative analysis of Senegal and the United States. Although the two countries differ significantly in their historical and political contexts, both demonstrate how dominant languages function as mechanisms of political legitimacy and social inclusion. Drawing on literature from political theory, postcolonial studies, and sociolinguistics, the study investigates the historical development of French linguistic dominance in Senegal and English linguistic hegemony in the United States. It analyzes how these language systems influence education, governance, civic participation, and public policy while also examining forms of linguistic resistance and hybridity. The analysis introduces a comparative framework that conceptualizes Senegal as an example of hierarchical pluralism, where multilingual practices coexist with institutional inequality, and the United States as an example of monolingual pluralism, where formal multilingual accommodations exist alongside the ideological dominance of English. The findings demonstrate that linguistic hierarchies continue to shape democratic participation and access to political legitimacy despite policy reforms promoting inclusion. The study concludes that language is not merely a means of communication but a central instrument through which citizenship, authority, and national belonging are constructed. By comparing two rarely paired cases, the research contributes to broader debates on democracy, multilingualism, and postcolonial governance while offering a new framework for understanding the relationship between language and political power.