A constitutional power specifically delegated to the federal government is the power to

The Constitution enumerates a great many powers of Congress, ranging from seemingly major powers, such as the powers to regulate interstate and foreign commerce, to seemingly more minor powers, such as the power to establish post offices and post roads. But there are many powers that most people, today or in 1788 (when the Constitution was ratified), would expect Congress to exercise that are not part of those enumerations. The Constitution assumes that there will be federal departments, offices, and officers, but no clause expressly gives Congress power to create them. Congress is given specific power to punish counterfeiting and piracy, but there is no explicit general authorization to provide criminal—or civil – penalties for violating federal law. Several constitutional provisions give Congress substantial authority over the nation’s finances, but no clause discusses a national bank or federal corporations.

These unspecified but undoubted congressional powers, and many others, emerge from the Clause at the end of Article I, Section 8, which gives Congress power “[t]o make all Laws which shall be necessary and proper for carrying into Execution” the other federal powers granted by the Constitution. This residual clause—called at various times the “Elastic Clause,” the “Sweeping Clause,” and (from the twentieth century onward) the “Necessary and Proper Clause”—is the constitutional source of the vast majority of federal laws. Virtually all of the laws establishing the machinery of government, as well as substantive laws ranging from antidiscrimination laws to labor laws, are enacted under the authority of the Necessary and Proper Clause. This Clause just might be the single most important provision in the Constitution.

At first glance (and keep in mind that first glances are not always last glances), close analysis of the words of the Necessary and Proper Clause suggests three criteria for a federal law to be within its scope: Laws enacted pursuant to the Clause must be (1) necessary, (2) proper, and (3) for carrying into execution some other federal power.

Historically, most of the controversy surrounding the meaning of the Necessary and Proper Clause has centered on the word “necessary.” In the 1790s during the Washington administration, and again two decades later in the Supreme Court, attempts to create a national bank in order to aid the nation’s finances generated three competing understandings of what kind of connection with another federal power makes a law “necessary” for implementing that power. Those understandings ranged from a strictly essential connection “without which the [implemented] grant of power would be nugatory” (Thomas Jefferson), to an intermediate requirement of “some obvious and precise affinity” between the implemented power and the implementing law (James Madison), to a very loose requirement allowing any law that “might be conceived to be conducive” to executing the implemented power (Alexander Hamilton).  In McCulloch v. Maryland (1819), the Supreme Court’s most famous case interpreting the Necessary and Proper Clause, the Court sided with Hamilton, giving Congress very broad authority to determine what is “necessary” for implementing federal powers. Subsequent cases have been at least as generous to Congress, finding necessity whenever one can imagine a “rational basis” for connecting implementing means to legislative ends. Indeed, no congressional law has ever been held unconstitutional by the Supreme Court on the stated ground that it was not “necessary” to implement a federal power.

Until quite recently, the word “proper” played no serious role in constitutional debates about the meaning of the clause. Indeed, a number of Founding-era figures, including such luminaries as Patrick Henry, James Monroe, and Daniel Webster, thought that the word “proper” was surplusage that added nothing to the word “necessary.” In 1997, however, following some academic commentary that sought to give substance to the requirement of propriety, the Supreme Court held in Printz v. United States that a federal law compelling state executive officials to implement federal gun registration requirements was not “proper” because it did not respect the federal/state boundaries that were part of the Constitution’s background or structure. Some later cases extended that holding to other matters involving federal/state relations. In NFIB v. Sebelius (2012), a constitutional challenge to “Obamacare,” the federal health care law, the Court sharply divided over whether a law could ever fail to be “proper” if it did not involve direct federal regulation of state governments or state officials. The subject is likely to be a point of contention in the future.

There was also little action until recently regarding what it means for a law to be “for carrying into Execution” another federal power. For a long time, the standard assumption has been that laws can carry federal powers into execution by making other laws grounded in those powers more effective. For example, the Court assumed in Missouri v. Holland (1920) that Congress could use the Necessary and Proper Clause to “carry[] into Execution” the treaty power by implementing and extending the substantive terms of a treaty. In recent years, however, three Justices have followed the lead of certain legal scholars by arguing that carrying the treaty power into execution means providing funds for ambassadors, pens and ink, and travel to foreign nations—in other words, it means making it possible to negotiate, draft, and ratify a treaty rather than to make the treaty more effective once it is negotiated, drafted, and ratified. Again, this subject is likely to be a point of contention in the future.

All of the foregoing, however, assumes that the right way to interpret the Necessary and Proper Clause is to pick apart its individual words and give each key term an independent meaning. That is not the only way to interpret the clause. Instead, one might look at the clause as a single, undifferentiated provision and try to discern the range of laws that the Clause, viewed holistically and purposively, tries to authorize.

One such vision (reflected in one of our separate statements) sees the Clause as a codification of principles of agency law that allow agents to exercise certain defined powers that are “incidental” to the main objects of the documents that empower the agents. Another such vision (reflected in the other of our separate statements) views the Clause as carrying forward ideas from a resolution adopted by the Constitutional Convention that would allow Congress to legislate “in all cases for the general interests of the Union . . . and in those to which the states are separately incompetent.” 

If the Necessary and Proper Clause has a relatively broad scope, as the second vision and two centuries of case law has largely maintained, it provides constitutional authorization for much of the existing federal machinery. If it has a narrower scope, as the first vision and a small but vocal group of Justices and scholars maintains, a great many federal laws that have been taken for granted for a long time might be called into question. The correct interpretation of the Necessary and Proper Clause might – just might – be the single most important question of American constitutional law.

The original Constitution of 1788 contained very few specific restrictions on the ways in which the power of the national government could be exercised against the people. It guaranteed the right to trial by jury in criminal (but not civil) cases, placed limits on prosecutions and punishments for treason, forbade bills of attainder (laws aimed at particular persons) and ex post facto laws (laws that punished conduct that was legal when it happened), limited any restrictions on habeas corpus to certain designated emergencies, and prohibited the granting of titles of nobility. But the Constitution that emerged from the 1787 Constitutional Convention contained nothing like a comprehensive bill of rights. Most state constitutions of the time had bills of rights, and many citizens—and members of the Constitutional Convention—expected the new national constitution to have one as well. Nonetheless, the state delegations at the Constitutional Convention voted 10-0 against including a bill of rights in the Constitution.

The sense of the Convention delegates was that a bill of rights, in the context of the federal Constitution, was unnecessary and even dangerous. It was considered unnecessary because the national government was a limited government that could only exercise those powers granted to it by the Constitution, and it had been granted no power to violate the most cherished rights of the people. There was, for example, no need for a provision protecting freedom of speech against Congress because, as James Wilson put it, “there is given to the general government no power whatsoever concerning it.” Edmund Randolph made the same point regarding freedom of religion, emphasizing that “[n]o part of the Constitution, even if strictly construed, will justify a conclusion that the general government can take away or impair the freedom of religion.” Similar remarks were made during the drafting and ratification process regarding juries in civil cases, general warrants, and cruel and unusual punishment. The consistent line of the Constitution’s defenders was that no bill of rights was necessary because the limited and enumerated powers of the national government simply did not include the power to violate those rights.

They even maintained that inclusion of a bill of rights would be dangerous, because it might suggest that the national government had powers that it had not actually been granted. As Alexander Hamilton put it, bills of rights “would contain various exceptions to powers not granted; and on this very account, would afford a colourable pretext to claim more than were granted. For why declare that things shall not be done, which there is no power to do?” Moreover, any list of rights would be incomplete. Such a list might indirectly endanger any rights not included on it.

In sum, the Constitution’s Framers thought that a bill of rights was appropriate for an unlimited government, but not for a limited one like the national government created by the Constitution. The Constitution accordingly sought to secure liberty through enumerations of powers to the government rather than through enumerations of rights to the people.

Not everyone was convinced by these arguments. Indeed, the absence of a bill of rights threatened to derail ratification of the Constitution, especially in key states such as Massachusetts and Virginia.  A number of states ratified the Constitution only on the express understanding that the document would quickly be amended to include a bill of rights. The first Congress accordingly proposed twelve Amendments, the last ten of which were ratified in 1791 and now stand as the Bill of Rights.

The first eight of those ratified Amendments identify various rights of the people involving such things as speech, religion, arms, searches and seizures, jury trials, and due process of law. The last two address the concerns of the Constitution’s defenders that these enumerations of rights were pointless and even dangerous.

The Ninth Amendment warns against drawing any inferences about the scope of the people’s rights from the partial listing of some of them. The Tenth Amendment warns against using a list of rights to infer powers in the national government that were not granted. In referring, respectively, to “rights . . .  retained by the people” and “powers . . .  reserved  . . . to the people,” the Ninth and Tenth Amendments also evoke themes of popular sovereignty, highlighting the foundational role of the people in the constitutional republic.

The Tenth Amendment’s simple language—“The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people”—emphasizes that the inclusion of a bill of rights does not change the fundamental character of the national government. It remains a government of limited and enumerated powers, so that the first question involving an exercise of federal power is not whether it violates someone’s rights, but whether it exceeds the national government’s enumerated powers. 

In this sense, the Tenth Amendment is “but a truism.” United States v. Darby (1941). No law that would have been constitutional before the Tenth Amendment was ratified becomes unconstitutional simply because the Tenth Amendment exists. The only question posed by the Tenth Amendment is whether a claimed federal power was actually delegated to the national government by the Constitution, and that question is answered by studying the enumerated powers, not by studying the Tenth Amendment. That was the understanding of the Supreme Court for nearly two centuries.

Nonetheless, beginning in 1976, a line of cases has emerged that seems to give substantive constitutional content to the Tenth Amendment. In 1986, in Garcia v. San Antonio Metropolitan Transit Authority, a narrow majority of the Supreme Court held that a city was required to comply with federal labor laws, and that state sovereignty interests should be protected by the participation of states in the national political process, rather than by judicially-enforced principles of federalism. However, while Garcia has never been explicitly overruled, in subsequent cases the Court has indeed found judicially-enforceable limits on the power of the federal government to regulate states (and their political subdivisions) directly. So it is now meaningful to speak of “Tenth Amendment doctrine.” Those cases all involve action by the federal government that in some way regulates or commands state governments, such as by telling states what policies they must adopt, New York v. United States (1992), forcing state or local executive officials to implement federal laws, Printz v. United States (1997), or conditioning the states’ acceptance of federal money on compliance with certain conditions, South Dakota v. Dole (1987). Interestingly, the Tenth Amendment has not been invoked by the Court to protect individual citizens against the exercise of federal power.

Whether the Tenth Amendment actually is, or ought to be, serving as an independent source of constitutional principles of federalism is a matter of great controversy, both on and off the Court. Do these “Tenth Amendment” cases really involve the Tenth Amendment, or do they simply interpret (or perhaps misinterpret) specific grants of federal power in light of certain principles codified in the Tenth Amendment, but present in the Constitution’s structure and design even before the Bill of Rights was ratified?