Selective Activism: Co‐Partisan Engagement in US Foreign Policy

ABSTRACT In the US Congress, rising partisanship in foreign policymaking has heightened pressure on co‐partisans to defer to the president. Simultaneously, post–Cold War expectations for congressional engagement have pushed legislators to be more active in foreign affairs. How do co‐partisan members balance these conflicting demands? This paper argues that co‐partisan legislators navigate these competing pressures through selective activism, rather than simply delegating foreign‐policy authority to the executive. Analyzing the cosponsorship of foreign policy bills, the study demonstrates that co‐partisans maintain engagement by promoting policies aligned with their president while strategically avoiding those that conflict with the administration's agenda. Furthermore, the analysis shows that cosponsorship significantly increases the likelihood of final passage, indicating that selective activism carries substantive policy consequences. By illuminating the nuances of co‐partisan engagement, this study broadens our understanding of how partisanship and activism interact to shape congressional behavior in a domain traditionally dominated by the president.