Every bill, order, resolution, or vote that must be passed by both Houses, except on a question of adjournment, must be presented to the President before becoming law. However, to propose a constitutional amendment, two-thirds of both Houses may submit it to the states for the ratification, without any consideration by the President, as prescribed in Article V.
Congress's legislative powers are enumerated in Section Eight:
Many powers of Congress have been interpreted broadly. Most notably, the Taxing and Spending, Interstate Commerce, and Necessary and Proper Clauses have been deemed to grant expansive powers to Congress.
Congress may lay and collect taxes for the "common defense" or "general welfare" of the United States. The U.S. Supreme Court has not often defined "general welfare," leaving the political question to Congress. In "United States v. Butler" (1936), the Court for the first time construed the clause. The dispute centered on a tax collected from processors of agricultural products such as meat; the funds raised by the tax were not paid into the general funds of the treasury, but were rather specially earmarked for farmers. The Court struck down the tax, ruling that the general welfare language in the Taxing and Spending Clause related only to "matters of national, as distinguished from local, welfare". Congress continues to make expansive use of the Taxing and Spending Clause; for instance, the social security program is authorized under the Taxing and Spending Clause.
Congress has the power to borrow money on the credit of the United States. In 1871, when deciding "Knox v. Lee," the Court ruled that this clause permitted Congress to emit bills and make them legal tender in satisfaction of debts. Whenever Congress borrows money, it is obligated to repay the sum as stipulated in the original agreement. However, such agreements are only "binding on the conscience of the sovereign", as the doctrine of sovereign immunity prevents a creditor from suing in court if the government reneges its commitment.
The Supreme Court has seldom restrained the use of the "commerce clause" for widely varying purposes. The first important decision related to the commerce clause was "Gibbons v. Ogden", decided by a unanimous Court in 1824. The case involved conflicting federal and state laws: Thomas Gibbons had a federal permit to navigate steamboats in the Hudson River, while the other, Aaron Ogden, had a monopoly to do the same granted by the state of New York. Ogden contended that "commerce" included only buying and selling of goods and not their transportation. Chief Justice John Marshall rejected this notion. Marshall suggested that "commerce" included navigation of goods, and that it "must have been contemplated" by the Framers. Marshall added that Congress's power over commerce "is complete in itself, may be exercised to its utmost extent, and acknowledges no limitations other than are prescribed in the Constitution".
The expansive interpretation of the Commerce Clause was restrained during the late nineteenth and early twentieth centuries, when a "laissez-faire" attitude dominated the Court. In "United States v. E. C. Knight Company" (1895), the Supreme Court limited the newly enacted Sherman Antitrust Act, which had sought to break up the monopolies dominating the nation's economy. The Court ruled that Congress could not regulate the manufacture of goods, even if they were later shipped to other states. Chief Justice Melville Fuller wrote, "commerce succeeds to manufacture, and is not a part of it."
The U.S. Supreme Court sometimes ruled New Deal programs unconstitutional because they stretched the meaning of the commerce clause. In "Schechter Poultry Corp. v. United States," (1935) the Court unanimously struck down industrial codes regulating the slaughter of poultry, declaring that Congress could not regulate commerce relating to the poultry, which had "come to a permanent rest within the State." As Chief Justice Charles Evans Hughes put it, "so far as the poultry here in question is concerned, the flow of interstate commerce has ceased." Judicial rulings against attempted use of Congress's Commerce Clause powers continued during the 1930s.
In 1937, the Supreme Court began moving away from its laissez-faire attitude concerning Congressional legislation and the Commerce Clause, when it ruled in "National Labor Relations Board v. Jones & Laughlin Steel Company", that the National Labor Relations Act of 1935 (commonly known as the Wagner Act) was constitutional. The legislation under scrutiny, prevented employers from engaging in "unfair labor practices" such as firing workers for joining unions. In sustaining this act, the Court, signaled its return to the philosophy espoused by John Marshall, that Congress could pass laws regulating actions that even indirectly influenced interstate commerce.
This new attitude became firmly set into place in 1942. In "Wickard v. Filburn", the Court ruled that production quotas under the Agricultural Adjustment Act of 1938 were constitutionally applied to agricultural production (in this instance, home-grown wheat for private consumption) that was consumed purely intrastate, because its effect upon interstate commerce placed it within the power of Congress to regulate under the Commerce Clause. This decision marked the beginning of the Court's total deference to Congress' claims of Commerce Clause powers, which lasted into the 1990s.
"United States v. Lopez" (1995) was the first decision in six decades to invalidate a federal statute on the grounds that it exceeded the power of the Congress under the Commerce Clause. The Court held that while Congress had broad lawmaking authority under the Commerce Clause, the power was limited, and did not extend so far from "commerce" as to authorize the regulation of the carrying of handguns, especially when there was no evidence that carrying them affected the economy on a massive scale. In a later case, "United States v. Morrison" (2000), the justices ruled that Congress could not make such laws even when there was evidence of aggregate effect.
In contrast to these rulings, the Supreme Court also continues to follow the precedent set by "Wickard v. Filburn". In "Gonzales v. Raich" it ruled that the Commerce Clause granted Congress the authority to criminalize the production and use of home-grown cannabis even where states approve its use for medicinal purposes. The court held that, as with the agricultural production in the earlier case, home-grown cannabis is a legitimate subject of federal regulation because it competes with marijuana that moves in interstate commerce.
Congress may establish uniform laws relating to naturalization and bankruptcy. It may also coin money, regulate the value of American or foreign currency and punish counterfeiters. Congress may fix the standards of weights and measures. Furthermore, Congress may establish post offices and post roads (the roads, however, need not be exclusively for the conveyance of mail). Congress may promote the progress of science and useful arts by granting copyrights and patents of limited duration. Section eight, clause eight of Article One, known as the Copyright Clause, is the only instance of the word "right" used in the original constitution (though the word does appear in several Amendments). Though perpetual copyrights and patents are prohibited, the Supreme Court has ruled in "Eldred v. Ashcroft" (2003) that repeated extensions to the term of copyright do not constitute perpetual copyright; also note that this is the only power granted where the means to accomplish its stated purpose is specifically provided for. Courts inferior to the Supreme Court may be established by Congress.