Partisanship, Religion, and Issue Polarization in the United States: A Reassessment

Researchers debate the extent of issue polarization in the United States, as well as what role (if any) social identities such as partisanship and religion play in issue polarization. In an effort to answer these questions, we develop a theory that social identities may lead to issue polarization, as long as identifiers have the constraint necessary to connect their identities to each issue. Using this theory, we hypothesize that partisanship should structure polarization on nearly any salient issues, while the impact of religious identities should be concentrated among cultural issues. We then introduce an original measure of issue polarization that allows us to capture the "depth" of issue polarization on five cultural issues (abortion, same-sex marriage, teaching Intelligent Design in public schools, displaying the Ten Commandments on government property, and anti-transgender bathroom bills) and five non-cultural issues (welfare, healthcare, immigration, the environment, and the size of the military). Relying on data from an original survey fielded in February 2020, we find evidence that a sizeable minority of the population holds polarized views on each issue. In addition, we find that partisanship structures polarization on nearly all of these issues, while religion's impact is mostly concentrated on cultural issues. Our findings help clarify academic debates about the origins and extent of issue polarization by demonstrating that a sizeable minority of the public holds polarized views on these issues, and that social identities such as partisanship and religion are important factors in that polarization.