and expanded. The nature of these expansions will appear from the nature of the federal government. It is a government of delegated and specified powers. The people have entrusted to it, not the plenitude of their own authority but certain enumerated functions, and its lawful action is limited to these functions. Hence, when the federal executive does an act, or the federal legislature passes a law, the question arises, Is the power to do this act or pass this law one of the powes which the people have by the Constitution delegated to their agents? The power may never have been exerted before. It may not be found expressed, in so many words, in the Constitution. Nevertheless it may, upon the true construction of that instrument, taking one clause with another, be held to be therein contained.
Now the doctrines laid down by Chief Justice Marshall, and on which the courts have constantly since proceeded, may be summed up in two propositions.
1. Every power alleged to be vested in the national government, or any organ thereof, must be affirmatively shown to have been granted. There is no presumption in favour of the existence of a power; on the contrary, the burden of proof lies on those who assert its existence, to point out something in the Constitution which, either expressly or by necessary implication, confers it. Just as an agent, claiming to act on behalf of his principal, must make out by positive evidence that his principal gave him the authority he relies on; so Congress, or those who rely on one of its statutes, are bound to show that the people have authorized the legislature to pass the statute. The search for the power will be conducted in a spirit of strict exactitude, and if there be found in the Constitution nothing which directly or impliedly conveys it, then whatever the executive or legislature of the national government, or both of them together, may have done in the persuasion of its existence, must be deemed null and void, like the act of any other unauthorized agent.7
2. When once the grant of a power by the people to the national government has been established, that power will be construed broadly. The strictness applied in determining its existence gives place to liberality in supporting its application. The people—so Marshall and his successors have argued—when they confer a power, must be deemed to confer a wide discretion as to the means whereby it is to be used in their service. For their main object is that it should be used vigorously and wisely, which it cannot be if the choice of methods is narrowly restricted; and while the people may well be chary in delegating powers to their agents, they must be presumed, when they do grant these powers, to grant them with confidence in the agents’ judgment, allowing all that freedom in using one means or another to attain the desired end which is needed to ensure success.8 This, which would in any case be the common-sense view, is fortified by the language of the Constitution, which authorizes Congress “to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this Constitution in the Government of the United States, or in any department or office thereof.” The sovereignty of the national government, therefore, “though limited to specified objects, is plenary as to those objects” 9 and supreme in its sphere. Congress, which cannot go one step beyond the circle of action which the Constitution has traced for it, may within that circle choose any means which it deems apt for executing its powers, and is in its choice of means subject to no review by the courts in their function of interpreters, because the people have made their representatives the sole and absolute judges of the mode in which the granted powers shall be employed. This doctrine of implied powers, and the interpretation of the words “necessary and proper,” were for many years a theme of bitter and incessant controversy among American lawyers and publicists.10 The history of the United States is in a large measure a history of the arguments which sought to enlarge or restrict its import. One school of statesmen urged that a lax construction would practically leave the states at the mercy of the national government, and remove those checks on the latter which the Constitution was designed to create; while the very fact that some powers were specifically granted must be taken to import that those not specified were withheld, according to the old maxim expressio unius exclusio alterius, which Lord Bacon concisely explains by saying, “as exception strengthens the force of a law in cases not excepted, so enumeration weakens it in cases not enumerated.” It was replied by the opposite school that to limit the powers of the government to those expressly set forth in the Constitution would render that instrument unfit to serve the purposes of a growing and changing nation, and would, by leaving men no legal means of attaining necessary but originally uncontemplated aims, provoke revolution and work the destruction of the Constitution itself.11
This latter contention derived much support from the fact that there were certain powers that had not been mentioned in the Constitution, but which were so obviously incident to a national government that they must be deemed to be raised by implication.12 For instance, the only offences which Congress is expressly empowered to punish are treason, the counterfeiting of the coin or securities of the government, and piracies and other offences against the law of nations. But it was very early held that the power to declare other acts to be offences against the United States, and punish them as such, existed as a necessary appendage to various general powers. So the power to regulate commerce covered the power to punish offences obstructing commerce; the power to manage the post office included the right to fix penalties on the theft of letters; and, in fact, a whole mass of criminal law grew up as a sanction to the civil laws which Congress had been directed to pass.
The three lines along which this development of the implied powers of the government has chiefly progressed, have been those marked out by the three express powers of taxing and borrowing money, of regulating commerce, and of carrying on war. Each has produced a progeny of subsidiary powers, some of which have in their turn been surrounded by an unexpected offspring. Thus from the taxing and borrowing powers there sprang the powers to charter a national bank and exempt its branches and its notes from taxation by a state (a serious restriction on state authority), to create a system of customhouses and revenue cutters, to establish a tariff for the protection of native industry. Thus the regulation of commerce has been construed to include legislation regarding every kind of transportation of goods and passengers, whether from abroad or from one state to another, regarding navigation, maritime and internal pilotage, maritime contracts, etc., together with the control of all navigable waters not situate wholly within the limits of one state, the construction of all public works helpful to commerce between states or with foreign countries, the power to prohibit immigration, and finally a power to establish a railway commission and control all interstate traffic.13 The war power proved itself even more elastic. The executive and the majority in Congress found themselves during the War of Secession obliged to stretch this power to cover many acts trenching on the ordinary rights of the states and of individuals, till there ensued something approaching a suspension of constitutional guarantees in favour of the federal government.
The courts have occasionally gone even further afield, and have professed to deduce certain powers of the legislature from the sovereignty inherent in the national government. In its last decision on the legal tender question, a majority of the Supreme Court seems to have placed upon this ground, though with special reference to the section enabling Congress to borrow money, its affirmance of that competence of Congress to declare paper money a legal tender for debts, which the earlier decision of 1871 had referred to the war power. This position evoked a controversy of wide scope, for the question what sovereignty involves belongs as much to political as to legal science, and may be pushed to great lengths upon considerations with which law proper has little to do.
The above-mentioned instances of development have been worked out by the courts of law. But others are due to the action of the executive, or of the executive and Congress conjointly. Thus, in 1803, President Jefferson negotiated and completed the purchase of Louisiana, the whole vast possessions of France beyond the Mississippi. He believed himself to be exceeding any powers which the Constitution conferred; and desired to have an amendment to it passed, in order to validate his act. But Congress and the people did not share his scruples, and the approval of the legislature was deemed sufficient ratification for a step of transcendent importance, which no provision of the Constitution bore upon. In 1807 and 1808 Congress laid, by two statutes, an embargo on all shipping in United States ports, thereby practically
