All of these three classes of constitutional limitations are therefore necessary to the perpetuity of our government.  I do not wish to be understood as saying that every single limitation is essential.  There are some limitations that might be changed and something different substituted.  But the system of limitation must be continued if our governmental system is to continue—­if we are not to lose the fundamental principles of government upon which our Union is maintained and upon which our race has won the liberty secured by law for which it has stood foremost in the world.

Lincoln covered this subject in one of his comprehensive statements that cannot be quoted too often.  He said in the first inaugural: 

“A majority held in restraint by constitutional checks and limitations and always changing easily with deliberate changes of popular opinion and sentiments the only true sovereign of a free people.  Whoever rejects it does of necessity fly to anarchy or despotism.”

Rules of limitation, however, are useless unless they are enforced.  The reason for restraining rules arises from a tendency to do the things prohibited.  Otherwise no rule would be needed.  Against all practical rules of limitation—­all rules limiting official conduct, there is a constant pressure from one side or the other.  Honest differences of opinion as to the extent of power, arising from different points of view make this inevitable, to say nothing of those weaknesses and faults of human nature which lead men to press the exercise of power to the utmost under the influence of ambition, of impatience with opposition to their designs, of selfish interest and the arrogance of office.  No mere paper rules will restrain these powerful and common forces of human nature.

The agency by which, under our system of government, observance of constitutional limitation is enforced is the judicial power.  The constitution provides that “This constitution, and the laws of the United States which shall be made in pursuance thereof, and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the constitution or laws of any state to the contrary notwithstanding.”  Under this provision an enactment by Congress not made in pursuance of the constitution, or an enactment of a state contrary to the constitution, is not a law.  Such an enactment should strictly have no more legal effect than the resolution of any private debating society.  The constitution also provides that the judicial power of the United States shall extend to all cases in law and equity arising under the constitution and laws of the United States.  Whenever, therefore, in a case before a Federal court rights are asserted under or against some law which is claimed to violate some limitation of the constitution, the court is obliged to say whether the law does violate