19. The phrase “necessary and proper” practically includes all the purposes of government, and these the Constitution itself sets forth, as
To form a more perfect Union,
To establish justice,
To insure domestic tranquillity,
To provide for the common defense,
To promote the general welfare,
To secure the blessings of libertyto themselves (“the people of the United States”) and their posterity.[55]
This exercise of power by Congress is essentially political, and Congress alone is judge of “the choice of means and is empowered to use any means which are in fact conducive to the exercise of a power granted by the Constitution.”[56] This conclusion is inevitable. A legislative body could exist on no other principle. Thus it follows that necessity is supremacy, in the case of congressional legislation. To any understanding of American constitutional law, comprehension of this principle is fundamental.
20. May Congress abuse its powers? Possibly. The remedy is through popular election of members of either House, and repeal of the laws which—even though their constitutionality be sustained by the courts, may, in the judgment of the people, transcend limits popularly supposed to be placed on Congress. Thus there are two checks on congressional legislation: the courts of law and the votes of the people. It follows that the American sovereign—the people—may by their votes approve or condemn congressional legislation—approval or condemnation resulting in a continuance or a change of membership of Congress, in conformity to the relative strength of political parties. It is here that part of the unwritten constitution is disclosed. The written Constitution contains no reference to political parties, but actual government in the United States is by and through political parties who, as organized agencies of the public mind, give expression, in large measure, to the unwritten constitution. Interpretation of the Constitution, and of course, of the powers of Congress, is largely interpretation by political parties.
21. Two interpretations of the Constitution have evolved in America, the strict, or literal, commonly called the Jeffersonian, and the liberal, or interpretation according to the spirit of the Constitution, commonly called the Hamiltonian. Chief Justice Marshall was a disciple of Hamilton and enthroned his ideas in the decisions of the Supreme Court for thirty years, and these the first thirty years of the existence of the Court. Later judges, whatever their politics, have rarely departed from the course of interpretation laid down by Marshall. To what extent the political convictions of a judge determine his judicial decisions, and to what extent party doctrines find utterance in the decisions of courts of law are matters of opinion quite as diverse as the men who hold them. Yet, in order to understand American constitutional law it is necessary also to be familiar with American political and constitutional history. Without that history, that law lacks background and circumstance.[57]
22. In attempting, then, to understand the legislation of Congress, which is an exercise of delegated powers, it is also necessary to know the history of the times in which it was enacted. Thus the first ten amendments were added in response to a quite unanimous demand of the American people for what they considered at the time, 1789, an adequate protection of their fundamental rights. The Eleventh Amendment of 1798 grew out of the unwillingness of the people that a State should be made defendant in a federal court at the suit of a citizen of another State; therefore federal jurisdiction in such cases was denied. The Twelfth Amendment of 1804 was added to remedy a defect in the Constitution in the method and procedure of choosing the President and the Vice-President. The Thirteenth, Fourteenth, and Fifteenth Amendments, of 1865, 1868, and 1870, were added because of the negro race. The Sixteenth and Seventeenth Amendments, of 1913, were added after long agitation over direct taxation and the popular election of senators of the United States, the one essentially an economic, the other, a political question. The history of the times records how these amendments were brought about. So too does that history largely explain the legislation enacted by Congress by authority of these amendments.[58]
23. The essential fact as to the powers of Congress is of their limitation. Turning to the Constitution itself, one will find that it devotes nearly three times as much matter to legislative as to executive power; and nearly eight times as much matter to legislative as to judicial power. Doubtless this spatial distribution of powers (or limitation of powers) tells the whole story. Government is largely an affair of legislation. Essentially, government is the public business, controlled and administered for public or general purposes. Government, in a republic, may be said to express itself in laws. So important is this expression of the will of the sovereign, constitutional law consists almost wholly of the interpretation of legislation. This means that the principles of government are to be learned chiefly from the judicial decisions in particular cases; and this again means that the particular law having in due course come before the tribunal, that law, when tested by the supreme law of the land is sustained, or is declared to be without authority,—hence it is unconstitutional. In the final test, all legislation of Congress must stand the strain of this question: By what authority is this law made? We come then, sooner or later, in congressional legislation, to the supreme law of the land and to sovereignty in America,—“We, the people of the United States.”
24. It is a presumption of law, necessary in the conduct of government, that all acts of Congress are constitutional until pronounced unconstitutional by a competent judicial tribunal. An issue arising between parties involves a law. In deciding the issue the tribunal decides as to the constitutionality of the law, provided its constitutionality forms part of the issue. Unless the issue of the constitutionality arises and is before the tribunal, that body can make no decision respecting the constitutionality of the law. Thus whether or not the powers exercised by Congress, as expressed in a piece of legislation—exceed the powers granted to it by the Constitution is a question which Congress itself is powerless to decide. The Constitution itself does not so declare; on the other hand it does not provide that Congress shall be the final judge of its own powers. The principle regulative of the exercise by Congress of powers delegated to it is laid down by the Supreme Court:[59] “Let the end be legitimate, let it be within the scope of the Constitution, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consist with the letter and spirit of the Constitution, are constitutional.”