Times of heightened risk to the physical safety of their citizens inevitably cause democracies to recalibrate their institutions and processes and to reinterpret existing legal norms, with greater emphasis on security, and less on individual liberty, than in "normal" times. This article explores the ways in which the American courts have responded to the tension between civil liberties and national security in times of crises. This history illustrates that courts have rejected both of the two polar positions that characterize public discourse on these issues. Civil libertarians argue that political bodies are too easily gripped by passions, hysteria, and self-interest in these times and that courts therefore ought to play a central role in protecting liberty. Executive unilateralists argue that the qualities that uniquely characterize the executive branch, such as decisiveness, access to information, and efficiency, must become so dominant in these moments that few checks, if any, should constrain executive prerogatives. Oddly, civil libertarians and executive unilateralists find implicit consensus in the view that, in times of war, courts have tended not to play a significant role in overseeing executive power. We argue to the contrary: historically, a significant constitutional tradition of judicial scrutiny in the United States during times of war does exist. But this scrutiny does not take the form of courts making first-order substantive judgments about the content of liberty or other claimed constitutional rights. Nor does it take the form of judicial assessment of how significant or credible the national security claims of the executive branch might be. Instead, judicial oversight has been focused on preserving the institutional structures and processes through which decisionmaking on these issues takes place. The judicial role has centered on the second-order question of whether the right institutional processes have been used to make the decisions at issue, rather than on what the content of the underlying rights ought to be. This approach has historically rejected or resisted most claims of executive unilateralism. When courts have upheld the government's actions, they have done so only after a judgment that Congress, as well as the executive, has endorsed the action. This approach has also rejected the civil libertarian framework. When courts find bilateral institutional endorsement, they have typically accepted the joint political judgment of how liberty and security tradeoffs ought to be made. By focusing on congressional endorsement of emergency measures, the courts have created a broad-based political accountability for the actions taken in the name of national security. We suggest that even if congressional endorsement is more apparent than real in some of these contexts, the judicial maintenance of this structure of rhetorical justifications sustains desirable understandings of political structure. Because the President and Congress draw from different political constituencies in a presidential rather than a parliamentary system, we also raise questions about whether the American judicial approach to these questions should be limited to political systems with separated executive and legislative powers.