Section 1
The judicial Power of the United States, shall be vested in one supreme Court,
and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in Office.
Interpretation:
The second sentence of Article III, Section 1, says: “The judges, both of the supreme and inferior courts, shall hold their offices during good behaviour, and shall, at stated times, receive for their services, a compensation, which shall not be diminished during their continuance in office.”
It’s pretty clear what’s going on here: this provision is designed to make sure that the judges are independent. They can decide cases according to what they think the law requires, without worrying about whether some powerful person—or even a majority of the people—will object. As Alexander Hamilton put it in
The Federalist No. 78, judicial independence “is the best expedient which can be devised in any government to secure a steady, upright, and impartial administration of the laws.”
Section 2
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.