The powers of Congress are limited to those specifically listed in Article I, Section 8 and those determined to be “necessary and proper” to carry out those powers. The Article’s so-called “necessary and proper” or “elastic” clause creates the justification for Congress to exercise several “implied powers,” such as the passage of laws regulating the private possession of firearms.
In addition, Article III Section 3 of the Constitution grants Congress the power to assess punishment for the crime of treason, and Article IV Section 3 grants Congress the power to create rules and regulations considered “needful” in dealing with the U.S. territories or “other Property belonging to the United States.”
Perhaps the most important powers reserved to Congress by Article I, Section 8 are those to create taxes, tariffs and other sources of funds needed to maintain the operations and programs of the federal government and to authorize the expenditure of those funds. In addition to the taxation powers in Article I, the Sixteenth Amendment authorizes Congress to establish and provide for the collection of a national income tax. The power to direct the expenditure of federal funds, known as the “power of the purse,” is essential to the system of “checks and balances” by giving the legislative branch great authority over the executive branch, which must ask Congress for all of its funding and approval of the president’s annual federal budget.
The Enumerated Powers
The complete text of Article I, Section 8 creating the 17 enumerated powers of Congress reads as follows:
Article I - The Legislative Branch
Section 8
Clause 1: The Congress shall have Power To lay and collect Taxes, Duties, Imposts, and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States;
Clause 2: To borrow Money on the credit of the United States;
Clause 3: To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;
Clause 4: To establish a uniform Rule of Naturalization, and uniform Laws on the subject of Bankruptcies throughout the United States;
Clause 5: To coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures;
Clause 6: To provide for the Punishment of counterfeiting the Securities and current Coin of the United States;
Clause 7: To establish Post Offices and post Roads;
Clause 8: To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;
Clause 9: To constitute Tribunals inferior to the Supreme Court;
Clause 10: To define and punish Piracies and Felonies committed on the high Seas, and Offences against the Law of Nations;
Clause 11: To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;
Clause 12: To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
Clause 13: To provide and maintain a Navy;
Clause 14: To make Rules for the Government and Regulation of the land and naval Forces;
Clause 15: To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
Clause 16: To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;
Clause 17: To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the Acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings;
