Separation of powers under the United States Constitution

Legislative power

Congress has the sole power to legislate for the United States. Under the nondelegation doctrine, Congress may not delegate its lawmaking responsibilities to any other agency. In this vein, the Supreme Court held in the 1998 case Clinton v. City of New York that Congress could not delegate a "line-item veto" to the President, by powers vested in the government by the Constitution.

Where Congress does not make great and sweeping delegations of its authority, the Supreme Court has been less stringent. One of the earliest cases involving the exact limits of non-delegation was Wayman v. Southard 23 U.S. (10 Wet.) 1, 42 (1825). Congress had delegated to the courts the power to prescribe judicial procedure; it was contended that Congress had thereby unconstitutionally clothed the judiciary with legislative powers. While Chief Justice John Marshall conceded that the determination of rules of procedure was a legislative function, he distinguished between "important" subjects and mere details. Marshall wrote that "a general provision may be made, and power is given to those who are to act under such general provisions, to fill up the details." Marshall's words and future court decisions gave Congress much latitude in delegating powers. It was not until the 1930s that the Supreme Court held a delegation of authority unconstitutional. In a case involving the creation of the National Recovery Administration called A.L.A. Schechter Poultry, 295 U.S. 495 (1935), Congress could not authorize the president to formulate codes of "fair competition." It was held that Congress must set some standards governing the actions of executive officers. The Court, however, has deemed that phrases such as "just and reasonable," "public interest" and "public convenience" suffice.

Executive power

Executive power is vested, with exceptions and qualifications,[1] in the President. By law (Section 2.) the president becomes the Commander in Chief of the Army and Navy, Militia of several states when called into service, has power to make treaties and appointments to office "with the Advice and Consent of the Senate," receive Ambassadors and Public Ministers, and "take care that the laws be faithfully executed" (Section 3.) By using these words, the Constitution does not require the president to personally enforce the law; rather, officers subordinate to the president may perform such duties. The Constitution empowers the president to ensure the faithful execution of the laws made by Congress and approved by the President. Congress may itself terminate such appointments, by impeachment, and restrict the president. Bodies such as the War Claims Commission (created by the War Claims Act of 1948), the Interstate Commerce Commission, and the Federal Trade Commission—all quasi-judicial—often have direct Congressional oversight. Congress often writes legislation to restrain executive officials to the performance of their duties, as laid out by the laws Congress passes. In Immigration and Naturalization Service v. Chadha (1983), the Supreme Court decided (a) The prescription for legislative action in Art. I, § 1—requiring all legislative powers to be vested in a Congress consisting of a Senate and a House of Representatives—and § 7—requiring every bill passed by the House and Senate, before becoming law, to be presented to the president, and, if he disapproves, to be repassed by two-thirds of the Senate and House—represents the Framers' decision that the legislative power of the Federal Government be exercised in accord with a single, finely wrought and exhaustively considered procedure. This procedure is an integral part of the constitutional design for the separation of powers. Further rulings clarified the case; even both Houses acting together cannot override Executive vetos without a ​2⁄3 majority. Legislation may always prescribe regulations governing executive officers.

Judicial power

Judicial power—the power to decide cases and controversies—is vested in the Supreme Court and inferior courts established by Congress. The judges must be appointed by the president with the advice and consent of the Senate, hold office during good behavior and receive compensations that may not be diminished during their continuance in office. If a court's judges do not have such attributes, the court may not exercise the judicial power of the United States. Courts exercising the judicial power are called "constitutional courts." Congress may establish "legislative courts," which do not take the form of judicial agencies or commissions, whose members do not have the same security of tenure or compensation as the constitutional court judges. Legislative courts may not exercise the judicial power of the United States. In Murray's Lessee v. Hoboken Land & Improvement Co. (1856), the Supreme Court held that a legislative court may not decide "a suit at the common law, or in equity, or admiralty," as such a suit is inherently judicial. Legislative courts may only adjudicate "public rights" questions (cases between the government and an individual and political determinations).