Religious minorities become politically suspect when religion ties into national identity. [causal]
An outcome of this close association of religion with national interest and identity in American history has been to leave religious differences open to politicization. Religious minorities find themselves not only theologically but also politically suspect as doubts are raised about their national loyalties and adherence to democratic principles. In the mid-nineteenth century, as the United States was moving closer to civil war, the nativist American Party elected six governors in 1855 on a platform of national homogeneity and "American feeling" fueled largely by anti-Catholic sentiments and opposition to new Catholic immigrants.
XREF: Connects to contemporary debates about religious minorities and national loyalty, as well as political nativism in other eras and countries.
Carl W. Ernst, Islamophobia in America_ Th…, loc. 272