At The Water’s Edge

Measuring Bipartisan Cooperation on National Security and Foreign Policy in Congress, 1945-2009
April 2010

This report provides the first statistical analysis of Congressional bipartisanship on national security and foreign policy issues, confirming anecdotal evidence of rising partisanship with hard data. In addition, the report analyzes causes of partisanship and provides recommendations for restoring the bipartisan center in Congress.

The past half century has witnessed a pronounced shift away from the tradition of bipartisan foreign policy and toward partisan polarization of all political debates, including those dealing

with the country’s basic national security interests. Experts, advocates, and politicians themselves have taken note of this trend, citing anecdotal evidence of a broad “partisan drift” in American politics. However, to date, there has been little formal study of the role of partisan politics in national security and foreign policy decision-making in Washington. This report seeks to address that gap by measuring bipartisanship and partisanship in Congressional voting records on national security and foreign policy from the end of World War II to the present. Based on this analysis of over six decades of Congressional voting, the Report concludes that there is indeed an overall trend of increased partisanship in national security and foreign policy voting, despite significant upward and downward variation in the short term.