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

The government of the Union, then, … is, emphatically, and truly, a government of the people. In form and in substance it emanates from them. Its powers are granted by them, and are to be exercised directly on them, and for their benefit.

This government is acknowledged by all to be one of enumerated powers. The principle, that it can exercise only the powers granted to it, would seem too apparent to have required to be enforced by all those arguments which it enlightened friends, while it was depending before the people, found it necessary to urge. That principle is now universally admitted. But the question respecting the extent of the powers actually granted, is perpetually arising, and will probably continue to arise, as long as our system shall exist.

...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.