Foreign Policy Ideological Orientation and US Legislative Debate

• In Event: Congress and Foreign Policy

Abstract

What shapes US legislative debate on foreign affairs? In conceptualizing legislative debate on
foreign policy issues, previous studies have largely focused on the role of presidential
leadership or the role of partisan politics. While they are good proxies, this study looks into the
role of the ideological orientations of individual legislators to more rigorously understand the
formation of legislative debate on foreign affairs. Contrary to previous assumptions in the
literature, this paper argues that ideological divisions within Congress on foreign policy are not
as muted as previously assumed. Instead of blindly following the decision of the president or
parties, legislators evaluate foreign policies through their own ideological lens. Legislators’
personal preferences about whether and how the United States should engage in world affairs
determine the level of their support and opposition. Foreign policy ideology adds more
interesting complexities to foreign policy debates as it creates further ideological variations not
only across different parties but also within each party. To examine whether ideology plays an
independent role in shaping legislative debates, this paper constructs an original dataset of the
US senators’ foreign policy ideological orientations. Specifically, I measure senators’
isolationist, cooperative, and militant preferences using a supervised machine learning method
on the US Senate’s floor speeches on a variety of foreign issues between 1947 and 2020. By
turning from aggregate models of party politics into more nuanced studies of foreign policy
ideology and individual member-level analysis, this research builds and tests theories of
legislative behavior in US foreign policy.

Author

• Sowon Park, University of Virginia