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Did the Supreme Court Violate or Vindicate the Constitution in the Latest Guantanamo Bay Decision? The Difference Between Separation of Powers and Checks and Balances


Monday, Jun. 16, 2008

Not surprisingly, last week’s landmark 5-4 Supreme Court ruling in Boumediene v. Bush has already been decried by conservatives and hailed by liberals. Curiously, however, critics and admirers of the decision both appear to claim support from the same venerable principle: the balance of powers under the U.S. Constitution. Justice Anthony M. Kennedy’s opinion, conservatives say, violated the Constitution by failing to provide adequate deference to the political branches—Congress and the President—in wartime. Not so, say liberals. The Court vindicated the Constitution by acting as a vital check on one of the worst abuses government can commit: detention without trial.

How can the Constitution’s structure be invoked on both sides of this question? The answer is that the Constitution contains two distinct structural mechanisms for allocating power among the branches of the national government: (1) separation of powers; and (2) checks and balances. Although often conflated in high school civics classes, these concepts are distinct and sometimes conflict. Understanding the difference between them will help explain how the Court could divide so sharply over such fundamental matters.

What the Court Decided in Boumediene

The Boumediene case itself presented two questions. First, does the Constitution guarantee a right of habeas corpus to foreign detainees held as enemy combatants on territory over which the United States exercises plenary control but technically lacks sovereignty? A majority of the Court said it does.

Having found that neither the President nor Congress could simply eliminate the right of habeas corpus, the Court next asked whether the combined military and civilian process in place for determining whether particular detainees are in fact enemy combatants is an adequate substitute for habeas corpus. Finding that it is not, the Court ordered that the detainees be permitted to file habeas corpus petitions in federal district court.

The Role of Ideology in the Court’s Division

What explains the Court’s sharp divisions? Here, as in all highly-charged Supreme Court cases, the respective ideologies of the individual Justices must be a big part of the answer. Every one of the four dissenters is, overall, more conservative than every one of the five Justices in the majority.

Moreover, Justice Scalia’s dissent—joined in full by Chief Justice Roberts and Justices Thomas and Alito—is poisonously provocative. In just the opening paragraphs, Justice Scalia: (1) says the majority opinion “will almost certainly cause more Americans to be killed”; (2) adopts the Bush Administration’s highly misleading characterization of the Iraq war as part of the same struggle against radical Islamists as the military response to 9/11; and (3) cites an Office of Legal Counsel memorandum co-authored by John Yoo as authority for the proposition that the Bush Administration was entitled to assume that aliens held at Guantanamo Bay would be beyond the reach of U.S. courts.

Although more respectful in tone, a second dissent, authored by Chief Justice Roberts and joined by the other dissenters, also finds little fault with the Bush Administration’s detention policy. The Chief Justice begins by hailing the process afforded Guantanamo Bay detainees as “the most generous set of procedural protections ever afforded aliens detained by this country as enemy combatants,” and later refers to Guantanamo Bay as a “jurisdictionally quirky outpost”

In marked contrast, the majority opinion openly disdains the Bush Administration’s transparent effort to evade review by selecting Guantanamo Bay as a prison site precisely for its jurisdictional quirks. Justice Kennedy repeatedly dismisses such “formalism,” arguing instead that the reach of the writ depends on functional considerations.

A Methodological Disagreement?

The majority’s rejection of formalism suggests a methodological division on the Court that closely parallels ideological ones. Broadly speaking, formalism is the notion that formal criteria decide legal questions. In Boumediene, Justice Kennedy meant to reject the formal criterion of sovereignty—for Guantanamo, sovereignty is technically vested in Cuba—as the basis for determining whether the writ extends to a particular territory. In its place, he favored asking practical questions: Will a habeas court’s orders be obeyed? Will they be disruptive of military operations in an active theater of war? And so forth.

In other contexts, however, formalism can refer to the propositional logic of the law itself. Formalists believe that formal legal materials—especially enacted text like that of statutes or the Constitution—resolve legal questions, whereas functionalists often find that such materials are too imprecise to do the hard work in hard cases. Although all Justices sometimes write formalist opinions, it is fair to say that the four Boumediene dissenters are substantially more committed to formalism than the five Justices in the majority. Justice Scalia once even wrote (in his book, A Matter of Interpretation) “Long live formalism.” It is thus not especially surprising that the Court’s formalists would recoil from a strongly anti-formalist opinion.

Nor is it especially surprising that the Court would divide over the proper role of history in matters of constitutional interpretation. Here too, all of the Justices believe that the historical origins of a constitutional provision are relevant to its current construction. The four dissenters, however, are the most strongly originalist members of the Court. In Boumediene, they thought it a fatal weakness in the petitioners’ argument that prior to the adoption of the Constitution in 1789, no English court had ever issued a writ of habeas corpus on behalf of a prisoner held outside the sovereign territory of the Crown.

For Justice Kennedy and the other majority Justices, the history was at most a fuzzy starting point. For one thing, the majority pointed out that the relevant English history was silent, not negative: No reported English case granted or rejected a habeas petition from an alien outside the realm. For another, even if the early English history were indeed to be read as rejecting a habeas right for aliens beyond the realm, that may well have been because of practical concerns applicable in the Eighteenth Century, but not in the Twenty-First. The majority found no precise analogue to Guantanamo Bay in the early cases, and was left to reason from the purpose of the Suspension Clause itself: protecting personal liberty against arbitrary detention.

Separation of Powers Versus Checks and Balances

The Justices’ respective ideological and methodological dispositions may well suffice to explain their disagreement in Boumediene. However, another fault line can be found as well: between two venerable but often misunderstood principles—separation of powers on the one hand, and checks and balances on the other.

The principle of separation of powers says that each branch of government should be confined to its own role: the legislature makes the laws; the executive executes the laws; and the judiciary interprets the laws. Although the Constitution does not contain an express “separation of powers clause,” the principle can fairly be inferred from the Constitution’s overall structure and language: Separate articles vest the legislative, executive, and judicial powers in distinct branches. Furthermore, particular clauses prevent legislative trials (the Bill of Attainder Clause) and parliamentary rule (the Incompatibility Clause).

The principle of checks and balances says that the Constitution prevents overreaching by any one branch through the checking function of the others. Here too, there is no express “checks and balances clause,” but the principle can be inferred from what the Constitution does express. The President can veto legislation; Congress can, in turn, override the President’s veto; the Senate must confirm principal officers nominated by the President; and the courts ensure that the other branches act within the Constitution, exercising a power readily inferred from the Supremacy Clause and Article III.

A moment’s reflection will reveal the tension between separation of powers and checks and balances. In order to check legislative excesses through the veto power, the President must in fact take part in making law; in order to constrain the President, Congress can hold oversight hearings and withhold funding when it disapproves of his execution of the law; and in order to keep the judiciary within bounds, the President and Senate may opt to only confirm judges whose approach broadly fits the elected officials’ conception of the role. In each of these and other instances of checks and balances, the very idea of checking entails some interference by one branch with the actions of another.

The Constitution contains no master rule for deciding when powers must be separated and when they can be shared so as to facilitate checking. That presents no difficulties where the Constitution’s language is pellucid. For example, no one doubts that the President can veto acts of Congress. But such cases do not give rise to litigation, much less Supreme Court litigation. How the Court resolves hard structural cases will thus typically depend on which principle—separation of powers, or checks and balances—the Justices consider stronger in any given context.

In the Boumediene case, the dissenters thought that the separation principle ought to prevail because of the deference courts typically afford the political branches in wartime. Congress has the power to declare and fund war, while the President prosecutes war as Commander in Chief. The courts, in this view, have no war powers as such.

The Boumediene majority was unwilling to concede even on separationist turf. The Suspension Clause itself authorizes Congress to suspend habeas corpus if the public safety so requires because of rebellion or invasion, but, Justice Kennedy noted, Congress had not purported to suspend the writ, and even if 9/11 could be characterized as an “invasion,” it hardly follows that public safety required suspending the writ. After all, the civilian courts have remained open, including for the trial of terrorism suspects.

Furthermore, the Boumediene majority was unwilling to concede that the case ought to be handled under a separation-of-powers, rather than a checks-and-balances, paradigm.

Separation of powers is partly about constraining government. Accumulation of all powers into one branch, Montesquieu and the Framers warned, is the very definition of tyranny. Accordingly, separating powers checks tyranny.

However, it does so less robustly than the checks and balances principle. The latter says that even within their respective spheres of competence, each branch can act capriciously. In the competition between the two principles, separation of powers is about leaving each branch to do what it is most competent doing, while checks and balances is about blocking abuses: ambition countering ambition, in James Madison’s phrase.

Seen in this light, Boumediene comes down to a question of trust. The dissenters believed that Congress and the President must be trusted to fashion and carry out war-related policies. The majority, in contrast, thought that Congress and especially this particular President had shown themselves unworthy of that trust.

Michael C. Dorf is the Isidor & Seville Sulzbacher Professor of Law at Columbia University. He is the author of No Litmus Test: Law Versus Politics in the Twenty-First Century and he blogs at

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