The enumerated powers are a list of items found in Article I, Section 8 of the U.S. Constitution that set forth the authoritative capacity of Congress. In summary, Congress may exercise the powers that the Constitution grants it, subject to explicit restrictions in the Bill of Rights and other protections in the Constitution. The Tenth Amendment states that "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
List of enumerated powers 
The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defense and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States;
To borrow on the credit of the United States;
To establish a uniform Rule of Naturalization, and uniform Laws on the subject of Bankruptcies throughout the United States;
To coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures;
To provide for the Punishment of counterfeiting the Securities and current Coin of the United States;
To constitute Tribunals inferior to the supreme Court;
To define and punish Piracies and Felonies committed on the high Seas, and Offenses against the Law of Nations;
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy;
To make Rules for the Government and Regulation of the land and naval Forces;
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
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;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 proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.]]
Political interpretation 
There is a difference of opinion in the political arena on whether current interpretation of enumerated powers as exercised by Congress is constitutionally sound.
"This government is acknowledged by all, to be one of enumerated powers. The principle, that it can exercise only the powers granted to it, would seem too apparent, to have required to be enforced by all those arguments, which its enlightened friends, while it was depending before the people, found it necessary to urge; that principle is now universally admitted."
Another school of thought is referred to as loose construction. They often reference additional comments by Justice Marshall from the same case:
"We admit, as all must admit, that the powers of the Government are limited, and that its limits are not to be transcended. But we think the sound construction of the Constitution must allow to the national legislature that discretion with respect to the means by which the powers it confers are to be carried into execution which will enable that body to perform the high duties assigned to it in the manner most beneficial to the people. Let the end be legitimate, let it be within the scope of the Constitution, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consistent with the letter and spirit of the Constitution, are constitutional," wrote Marshall.
Necessary and Proper Clause 
Interpretation of the Necessary and Proper Clause has been controversial, especially during the early years of the republic. Strict constructionists interpret the clause to mean that Congress may make a law only if the inability to do so would cripple its ability to apply one of its enumerated powers. Loose constructionists, on the other hand, interpret the Necessary and Proper Clause as expanding the authority of Congress to all areas tangentially-related to one of its enumerated powers. It is often known as the "elastic clause" because of the great amount of leeway in interpretation it allows; depending on the interpretation, it can be "stretched" to expand the powers of Congress, or allowed to "contract", limiting Congress. In practical usage, the clause has been paired with the Commerce Clause in particular to provide the constitutional basis for a wide variety of federal laws.
McCulloch v. Maryland 
The defining example of the Necessary and Proper Clause in U.S. history was McCulloch v. Maryland in 1819. The United States Constitution says nothing about establishing a national bank. The U.S. government established a national bank that provided part of the government's initial capital. In 1819 the federal government opened a national bank in Baltimore, Maryland. In an effort to tax the bank out of business, the government of Maryland imposed a tax on the federal bank. James William McCulloch, a cashier at the bank, refused to pay the tax. Eventually the case was heard before the U.S. Supreme Court. Chief Justice John Marshall held that the power of establishing a national bank could be implied from the U.S. constitution. Marshall ruled that no state could use its taxing power to tax an arm of the national government.
Recent Case Law 
The case of United States v. Lopez in 1997 held unconstitutional the Gun Free School Zone Act because it exceeded the power of Congress to "regulate commerce...among the several states". Chief Justice William Rehnquist wrote, "We start with first principles. The Constitution creates a Federal Government of enumerated powers." For the first time in sixty years the Court found that in creating a federal statute, Congress had exceeded the power granted to it by the Commerce Clause.
- For more details see: The Rehnquist Court and the Commerce Clause
In National Federation of Independent Business v. Sebelius, the Supreme Court held that the Commerce Clause did not give Congress the authority to require individuals to purchase health insurance. However, since the court ruled that Congress's taxing authority was sufficient to enact the mandate, some constitutional lawyers have argued that the commerce clause discussion should be treated as judicial dictum . Chief Justice John Roberts, in his majority opinion, stated that:
- [T]he statute reads more naturally as a command to buy insurance than as a tax, and I would uphold it as a command if the Constitution allowed it. It is only because the Commerce Clause does not authorize such a command that it is necessary to reach the taxing power question. And it is only because we have a duty to construe a statute to save it, if fairly possible, that §5000A can be interpreted as a tax. Without deciding the Commerce Clause question, I would find no basis to adopt such a saving construction.
No other justice joined this segment of the Chief Justice's opinion, though.
Enumerated Powers Act 
The Enumerated Powers Act is a proposed law that would require all bills introduced in the U.S. Congress to include a statement setting forth the specific constitutional authority under which each bill is being enacted. In every Congress since the 104th Congress, U.S. Congressman John Shadegg has introduced the Enumerated Powers Act, although it has not been passed into law. At the beginning of the 105th Congress, the House of Representatives incorporated the substantive requirement of the Enumerated Powers Act into the House rules.
Tea Party support 
The Enumerated Powers Act is supported by leaders of the U.S. Tea Party movement. National Tea Party leader Michael Johns has said that progressives often "see the Constitution as an impediment to their statist agenda. In almost all cases, though, there is very little thought or dialogue given to what should be the first and foremost question asked with every legislative or administrative governmental action: Is this initiative empowered to our federal government by the document's seven articles and 27 amendments? In many, many cases, the answer is no." "For this reason," Johns said, "we also strongly support the Enumerated Powers Act, which will require Congress to justify the Constitutional authority upon which all legislation is based."
See also 
- U.S. Constitution Online
- Exploring Constitutional Conflicts, UMKC
- McCulloch v. Maryland, 17 US 316 (S.Ct. 1819-03-06).
- UMKC "The Necessary and Proper Clause"
- Schmidt, Barbara A. Bardes, Mack C. Shelley, Steffen W. American government and politics today : the essentials, 2011-2012 (2011-2012 ed. ed.). Boston, MA: Wadsworth, Cengage Learning. ISBN 978-0-538-49719-0.
- 514 U.S. 549
- United States v. Lopez - Significance, Court Of Appeals Ruling, Supreme Court Ruling, Implications, Related Cases, Further Readings
- National Federation of Independent Business v. Sebelius, 567 US ___ (S.Ct. 2012-06-28).
- Schwinn, Steven D. (2012-06-29), Did Chief Justice Roberts Craft a New, More Limited Commerce Clause?
- Zadorozny, George (2012-07-11), Dicta in the NFIB v. Sebelius (Obamacare) Decision
- H.R. 2458
- John Shadegg
- "Interview with National Tea Party Founder and Leader Michael Johns", About.com
- Constitutional Studies, Tenth Amendment, Enumerated powers from the Cato Institute
- Annotations on enumerated powers from FindLaw
- Text of the Enumerated Powers Act
- Committees on Enumerated Powers: How Congress Can Revive the Constitution from the Center for Constitutional Studies