In August 2010, the father of Anwar al-Awlaki filed a federal lawsuit alleging that his son’s inclusion on CIA and DoD “kill lists” violated the Constitution and international law. The court dismissed the suit for lack of standing and for raising a political question. Several months later, the CIA killed Awlaki and two other U.S. citizens in aerial drone strikes in Yemen. Now the ACLU and Center for Constitutional Rights have responded by filing a separate lawsuit challenging the government’s use of the drones. The defendants are Leon Panetta, David Petraeus, and two other senior military officials, and the complaint alleges that the killings violated the Fourth and Fifth Amendments and the Bill of Attainder Clause. Given the relatedness of the lawsuits and the dismissal of the first on the basis of the political question doctrine, I think there’s very little chance that the second succeeds. But it still raises interesting issues.

One concerns precedent—has the United States ever carried out targeted killings against its own citizens? The answer is yes; the U.S. military has targeted and killed individuals without judicial process notwithstanding their U.S. citizenship. The most significant example comes from the Civil War, during which the Union killed tens of thousands of Confederate soldiers. One might argue that those soldiers were no longer U.S. citizens because they were fighting for the Confederacy, but that position is inconsistent with the view—supported by the Supreme Court’s decision in Texas v. White (1869)—that secession was unconstitutional. As long as secession was invalid, then the Confederacy was void and did not dissolve the U.S. citizenship of its soldiers. More isolated examples appear to have occurred during World War II, when the United States fought against Nazi forces that included some U.S. citizens of German descent. And of course federal law enforcement officers have occasionally killed criminal suspects who presented significant and immediate threats to the public. If the United States has acted permissibly in these cases, then the extrajudicial killing of a U.S. citizen is not unconstitutional per se.

Of course, it does not necessarily follow that the drone strike on Awlaki was constitutional. The Civil War and World War II are in important ways different from the war on terrorism—both fit into classic categories of armed conflict and presented more significant threats to the United States. And fatal police actions against suspected criminals are generally responses to threats more immediate than that presented by Awlaki. Moreover, even if these differences were immaterial, it’s not clear how much non-judicial precedent should guide the analysis—political branches disregard it all the time, and courts are poorly equipped to apply it.

A second question, then, concerns which criteria should determine the constitutionality of acts of this kind. One would think that the criteria should be extremely difficult to satisfy. If the Civil War and World War II precedents are any guide, then perhaps a targeted citizen must be actively fighting against the country in an armed conflict that presents an existential threat to the United States. As an alternative, a secret OLC opinion has reportedly suggested that the targeting must further a permissible military objective, and that the citizen must present an imminent threat and be beyond the reach of law enforcement.

Many have debated what the criteria should be, whether Awlaki satisfied them, and whether the political question doctrine should preclude judicial elaboration on the subject. But I think it’s hard to dispute that dismissing litigation on the basis of the doctrine generates at least one significant problem: Because terrorists such as Awlaki are far from popular and voters are generally apathetic about small-scale, overseas military operations, public opinion and Congress will hardly ever present a hurdle to targeting operations. Moreover, because the President’s criteria are secret, the public cannot know whether targeting decisions are justified. Once you couple those circumstances with the absence of judicial review, there is not much to ensure that the executive responsibly uses the power to target terrorism suspects who hold U.S. citizenship. To me, this is a bigger problem than the drone strikes themselves.