Does the U.S. Supreme Court curtail rights and liberties when the nation's security is under threat? In hundreds of articles and books, and with renewed fervor since September 11, 2001, members of the legal community have warred over this question. Yet, not a single large-scale, quantitative study exists on the subject. Using the best data available on the causes and outcomes of every civil rights and liberties case decided by the Supreme Court over the past six decades and employing methods chosen and tuned especially for this problem, our analyses demonstrate that when crises threaten the nation's security, the justices are substantially more likely to curtail rights and liberties than when peace prevails. Yet paradoxically, and in contradiction to virtually every theory of crisis jurisprudence, war appears to affect only cases that are unrelated to the war. For these cases, the effect of war and other international crises is so substantial, persistent, and consistent that it may surprise even those commentators who long have argued that the Court rallies around the flag in times of crisis. On the other hand, we find no evidence that cases most directly related to the war are affected.

We attempt to explain this seemingly paradoxical evidence with one unifying conjecture: Instead of balancing rights and security in high stakes cases directly related to the war, the Justices retreat to ensuring the institutional checks of the democratic branches. Since rights-oriented and process-oriented dimensions seem to operate in different domains and at different times, and often suggest different outcomes, the predictive factors that work for cases unrelated to the war fail for cases related to the war. If this conjecture is correct, federal judges should consider giving less weight to legal principles outside of wartime but established during wartime, and attorneys should see it as their responsibility to distinguish cases along these lines.

You may also be interested in a replication data file for this article, as well as the related paper and software we used: Daniel Ho, Kosuke Imai, Gary King, and Elizabeth Stuart, "Matching as Nonparametric Preprocessing for Improving Parametric Causal Inference," (Article: PDF | Abstract: HTML | Software: MatchIt). There is also a greatly abbreviated version of the paper written for an undergraduate audience: Epstein, Lee; Daniel E. Ho; Gary King; and Jeffrey A. Segal, "The Effect of War on the Supreme Court," in Samuel Kernell and Steven S. Smith, eds. (3rd ed). Principles and Practice in American Politics: Classic and Contemporary Readings. Washington, D.C.: Congressional Quarterly Press, 2006 (Article: PDF). Also see related research.