A legislative act contrary to the Constitution is not law.

A legislative act contrary to the Constitution is not law.

It is emphatically the province and duty of the Judicial Department to say what the law is.

Have no power, by taxation or otherwise, to retard, impede, burden or in any manner control the operations of the constitutional laws enacted by Congress.

State inspection laws, health laws, and laws for regulating the internal commerce of a State, and those which respect turnpike roads, ferries, &c. are not within the power granted to Congress. ... Inspection laws, quarantine laws, health laws of every description, as well as laws for regulating the internal commerce of a State, and those which respect turnpike roads, ferries, &c., are component parts of this mass. No direct general power over these objects is granted to Congress, and, consequently, they remain subject to State legislation.

No political dreamer was ever wild enough to think of breaking down the lines which separate the States and compounding the American people into one common mass.

The federal government is acknowledged by all to be one of enumerated powers. The principle, that it can exercise only the powers granted to it . . . is now universally admitted.