Article III, Section 2, Clause 1:
The Judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and Treaties made, or which shall be made, under their Authority;—to all Cases affecting Ambassadors, other public Ministers and Consuls;—to all Cases of admiralty and maritime Jurisdiction; to Controversies to which the United States shall be a Party;—to Controversies between two or more States; between a State and Citizens of another State; between Citizens of different States,—between Citizens of the same State claiming Lands under Grants of different States, and between a State, or the Citizens thereof, and foreign States, Citizens or Subjects.
It is but a decent respect to the wisdom, integrity, and patriotism of the legislative body, by which any law is passed, wrote Justice Bushrod Washington,
to presume in favor of its validity, until its violation of the Constitution is proved beyond a reasonable doubt. 1 A corollary of this maxim is that if the constitutional question turns upon circumstances, courts will presume the existence of a state of facts which would justify the legislation that is challenged. 2 It seems apparent, however, that with regard to laws which trench upon First Amendment freedoms and perhaps other rights guaranteed by the Bill of Rights such deference is far less than it would be toward statutory regulation of economic matters. 3