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.
Another maxim of constitutional interpretation is that courts are concerned only with the constitutionality of legislation and not with its motives, policy, or wisdom, 1 or with its concurrence with natural justice, fundamental principles of government, or the spirit of the Constitution. 2 In various forms this maxim has been repeated to such an extent that it has become trite, and has increasingly come to be incorporated in cases in which a finding of unconstitutionality has been made as a reassurance of the Court's limited review. And it should be noted that at times the Court has absorbed natural rights doctrines into the text of the Constitution, so that it was able to reject natural law per se and still partake of its fruits and the same thing is true of the laissez faire principles incorporated in judicial decisions from about 1890 to 1937. 3