Without their active co-operation the Constitution would be a dead letter: the Executive appeals to them for assistance against the encroachments of the legislative powers; the Legislature demands their protection from the designs of the Executive; they defend the Union from the disobedience of the States, the States from the exaggerated claims of the Union, the public interest against the interests of private citizens, and the conservative spirit of order against the fleeting innovations of democracy.

Their power is enormous, but it is clothed in the authority of public opinion.

They are the all-powerful guardians of a people which respects law, but they would be impotent against popular neglect or popular contempt.

The force of public opinion is the most intractable of agents, because its exact limits cannot be defined; and it is not less dangerous to exceed than to remain below the boundary prescribed.
The Federal judges must not only be good citizens, and men possessed of that information and integrity which are indispensable to magistrates, but they must be statesmen--politicians, not unread in the signs of the times, not afraid to brave the obstacles which can be subdued, nor slow to turn aside such encroaching elements as may threaten the supremacy of the Union and the obedience which is due to the laws.
The President, who exercises a limited power, may err without causing great mischief in the State.

Congress may decide amiss without destroying the Union, because the electoral body in which Congress originates may cause it to retract its decision by changing its members.
But if the Supreme Court is ever composed of imprudent men or bad citizens, the Union may be plunged into anarchy or civil war.
The real cause of this danger, however, does not lie in the constitution of the tribunal, but in the very nature of Federal Governments.