told us that it is a fundamental rule of our Constitution that any act of the legislature repugnant to the Constitution is void. In declaring what shall be the supreme law of the land, the Constitution itself is first mentioned; and not the laws of the United States generally, but those only which shall be made in pursuance of the Constitution, have that rank.
Deciding if a law is constitutional is not difficult, all one needs to do is have a familiarity with the unchangeable foundational principles of the Constitution to decide it.
"The question, whether an act, repugnant to the constitution, can become the law of the land, is a question deeply interesting to the United States; but, happily, not of an intricacy proportioned to its interest. It seems only necessary to recognise certain principles, supposed to have been long and well established, to decide it.
That the people have an original right to establish, for their future government, such principles as, in their opinion, shall most conduce to their own happiness, is the basis on which the whole American fabric has been erected. The exercise of this original right is a very great exertion; nor can it nor ought it to be frequently repeated. The principles, therefore, so established are deemed fundamental. And as the authority, from which they proceed, is supreme, and can seldom act, they are designed to be permanent.
This original and supreme will organizes the government, and assigns to different departments their respective powers. It may either stop here; or establish certain limits not to be transcended by those departments.
The government of the United States is of the latter description. The powers of the legislature are defined and limited; and that those limits may not be mistaken or forgotten, the constitution is written. To what purpose are powers limited, and to what purpose is that limitation committed to writing; if these limits may, at any time, be passed by those intended to be restrained? . . .
Certainly all those who have framed written constitutions contemplate them as forming the fundamental and paramount law of the nation, and consequently the theory of every such government must be, that an act of the legislature repugnant to the constitution is void.
This theory is essentially attached to a written constitution, and is consequently to be considered by this court as one of the fundamental principles of our society. . . .
If an act of the legislature, repugnant to the constitution, is void, does it, notwithstanding its invalidity, bind the courts and oblige them to give it effect? Or, in other words, though it be not law, does it constitute a rule as operative as if it was a law? This would be to overthrow in fact what was established in theory; and would seem, at first view, an absurdity too gross to be insisted on. . . .
From these and many other selections which might be made, it is apparent, that the framers of the constitution contemplated that instrument as a rule for the government of courts, as well as of the legislature.
Why otherwise does it direct the judges to take an oath to support it? This oath certainly applies, in an especial manner, to their conduct in their official character. How immoral to impose it on them, if they were to be used as the instruments, and the knowing instruments, for violating what they swear to support! . . .
Why does a judge swear to discharge his duties agreeably to the constitution of the United States, if that constitution forms no rule for his government? . . .
If such be the real state of things, this is worse than solemn mockery. To prescribe, or to take this oath, becomes equally a crime.
It is also not entirely unworthy of observation, that in declaring what shall be the supreme law of the land, the constitution itself is first mentioned; and not the laws of the United States generally, but those only which shall be made in pursuance of the constitution, have that rank.
Thus, the particular phraseology of the constitution of the United States confirms and strengthens the principle, supposed to be essential to all written constitutions, that a law repugnant to the constitution is void, and that courts, as well as other departments, are bound by that instrument."
MARBURY v. MADISON, 5 U.S. 137 (1803)