Full Case Name:  United States of America v. Lopez (Abridged for Purposes of Eagle Topic Area)

In the Gun-Free School Zones Act of 1990, Congress made it a federal offense "for any individual knowingly to possess a firearm at a place that the individual knows, or has reasonable cause to believe, is a school zone." 18 U.S.C. § 922(q)(1)(A) (1988 ed., Supp. V). The Act neither regulates a commercial activity nor contains a requirement that the possession be connected in any way to interstate commerce. We hold that the Act exceeds the authority of Congress "[t]o regulate Commerce ... among the several States...." U.S. Const., Art. I, § 8, cl. 3.

On March 10, 1992, respondent, who was then a 12th-grade student, arrived at Edison High School in San Antonio, Texas, carrying a concealed .38-caliber handgun and five bullets. Acting upon an anonymous tip, school authorities confronted respondent, who admitted that he was carrying the weapon. He was arrested and charged under Texas law with firearm possession on school premises. See Tex.Penal Code Ann. § 46.03(a)(1) (Supp.1994). The next day, the state charges were dismissed after federal agents charged respondent by complaint with violating the Gun-Free School Zones Act of 1990. 18 U.S.C. § 922(q)(1)(A) (1988 ed., Supp. V). [FN1]

FN1. The term "school zone" is defined as "in, or on the grounds of, a public, parochial or private school" or "within a distance of 1,000 feet from the grounds of a public, parochial or private school." § 921(a)(25).

A federal grand jury indicted respondent on one count of knowing possession of a firearm at a school zone, in violation of § 922(q). Respondent moved to dismiss his federal indictment on the ground that § 922(q) "is unconstitutional as it is beyond the power of Congress to legislate control over our public schools." The District Court denied the motion, concluding that § 922(q) "is a constitutional exercise of Congress' well-defined power to regulate activities in and affecting commerce, and the 'business' of elementary, middle and high schools ... affects interstate commerce." App. to Pet. for Cert. 55a. Respondent waived his right to a jury trial. The District Court conducted a bench trial, found him guilty of violating § 922(q), and sentenced him to six months' imprisonment and two years' supervised release.

On appeal, respondent challenged his conviction based on his claim that § 922(q) exceeded Congress' power to legislate under the Commerce Clause. The Court of Appeals for the Fifth Circuit agreed and reversed respondent's conviction. It held that, in light of what it characterized as insufficient congressional findings and legislative history, "section 922(q), in the full reach of its terms, is invalid as beyond the power of Congress under the Commerce Clause." 2 F.3d 1342, 1367-1368 (1993). Because of the importance of the issue, we granted certiorari, 511 U.S. 1029, 114 S.Ct. 1536, 128 L.Ed.2d 189 (1994), and we now affirm.

* * *

Consistent with this structure, we have identified three broad categories of activity that Congress may regulate under its commerce power. Perez, supra, at 150, 91 S.Ct., at 1359; see also Hodel, supra, at 276- 277, 101 S.Ct., at 2360-2361. First, Congress may regulate the use of the channels of interstate commerce. See, e.g., Darby, 312 U.S., at 114, 61 S.Ct., at 457; Heart of Atlanta Motel, supra, at 256, 85 S.Ct., at 357 (" '[T]he authority of Congress to keep the channels of interstate commerce free from immoral and injurious uses has been frequently sustained, and is no longer open to question.' " (quoting Caminetti v. United States, 242 U.S. 470, 491, 37 S.Ct. 192, 197, 61 L.Ed. 442 (1917))). Second, Congress is empowered to regulate and protect the instrumentalities of interstate commerce, or persons or things in interstate commerce, even though the threat may come only from intrastate activities. See, e.g., Shreveport Rate Cases, 234 U.S. 342, 34 S.Ct. 833, 58 L.Ed. 1341 (1914); Southern R. Co. v. United States, 222 U.S. 20, 32 S.Ct. 2, 56 L.Ed. 72 (1911) (upholding amendments to Safety Appliance Act as applied to vehicles used in intrastate commerce); Perez, supra, at 150, 91 S.Ct., at 1359 ("[F]or example, the destruction of an aircraft (18 U.S.C. § 32), or ... thefts from interstate shipments (18 U.S.C. § 659)"). Finally, Congress' commerce authority includes the power to regulate those activities having a substantial relation to interstate commerce, Jones & Laughlin Steel, 301 U.S., at 37, 57 S.Ct., at 624, i.e., those activities that substantially affect interstate commerce, Wirtz, supra, at 196, n. 27, 88 S.Ct., at 2024, n. 27.

Within this final category, admittedly, our case law has not been clear whether an activity must "affect" or "substantially affect" interstate commerce in order to be within Congress' power to regulate it under the Commerce Clause. Compare Preseault v. ICC, 494 U.S. 1, 17, 110 S.Ct. 914, 924-925, 108 L.Ed.2d 1 (1990), with Wirtz, supra, at 196, n. 27, 88 S.Ct., at 2024, n. 27 (the Court has never declared that "Congress may use a relatively trivial impact on commerce as an excuse for broad general regulation of state or private activities"). We conclude, consistent with the great weight of our case law, that the proper test requires an analysis of whether the regulated activity "substantially affects" interstate commerce.

We now turn to consider the power of Congress, in the light of this framework, to enact § 922(q). The first two categories of authority may be quickly disposed of: § 922(q) is not a regulation of the use of the channels of interstate commerce, nor is it an attempt to prohibit the interstate transportation of a commodity through the channels of commerce; nor can § 922(q) be justified as a regulation by which Congress has sought to protect an instrumentality of interstate commerce or a thing in interstate commerce. Thus, if § 922(q) is to be sustained, it must be under the third category as a regulation of an activity that substantially affects interstate commerce.

First, we have upheld a wide variety of congressional Acts regulating intrastate economic activity where we have concluded that the activity substantially affected interstate commerce. Examples include the regulation of intrastate coal mining; Hodel, supra, intrastate extortionate credit transactions, Perez, supra, restaurants utilizing substantial interstate supplies, McClung, supra, inns and hotels catering to interstate guests, Heart of Atlanta Motel, supra, and production and consumption of homegrown wheat, Wickard v. Filburn, 317 U.S. 111, 63 S.Ct. 82, 87 L.Ed. 122 (1942). These examples are by no means exhaustive, but the pattern is clear. Where economic activity substantially affects interstate commerce, legislation regulating that activity will be sustained.

Even Wickard, which is perhaps the most far reaching example of Commerce Clause authority over intrastate activity, involved economic activity in a way that the possession of a gun in a school zone does not. Roscoe Filburn operated a small farm in Ohio, on which, in the year involved, he raised 23 acres of wheat. It was his practice to sow winter wheat in the fall, and after harvesting it in July to sell a portion of the crop, to feed part of it to poultry and livestock on the farm, to use some in making flour for home consumption, and to keep the remainder for seeding future crops. The Secretary of Agriculture assessed a penalty against him under the Agricultural Adjustment Act of 1938 because he harvested about 12 acres more wheat than his allotment under the Act permitted. The Act was designed to regulate the volume of wheat moving in interstate and foreign commerce in order to avoid surpluses and shortages, and concomitant fluctuation in wheat prices, which had previously obtained. The Court said, in an opinion sustaining the application of the Act to Filburn's activity:

"One of the primary purposes of the Act in question was to increase the market price of wheat and to that end to limit the volume thereof that could affect the market. It can hardly be denied that a factor of such volume and variability as home-consumed wheat would have a substantial influence on price and market conditions. This may arise because being in marketable condition such wheat overhangs the market and, if induced by rising prices, tends to flow into the market and check price increases. But if we assume that it is never marketed, it supplies a need of the man who grew it which would otherwise be reflected by purchases in the open market. Home-grown wheat in this sense competes with wheat in commerce." 317 U.S., at 128, 63 S.Ct., at 90- 91.

Section 922(q) is a criminal statute that by its terms has nothing to do with "commerce" or any sort of economic enterprise, however broadly one might define those terms. [FN3] Section 922(q) is not an essential part of a larger regulation of economic activity, in which the regulatory scheme could be undercut unless the intrastate activity were regulated. It cannot, therefore, be sustained under our cases upholding regulations of activities that arise out of or are connected with a commercial transaction, which viewed in the aggregate, substantially affects interstate commerce.

FN3. Under our federal system, the " 'States possess primary authority for defining and enforcing the criminal law.' " Brecht v. Abrahamson, 507 U.S. 619, 635, 113 S.Ct. 1710, 1720, 123 L.Ed.2d 353 (1993) (quoting Engle v. Isaac, 456 U.S. 107, 128, 102 S.Ct. 1558, 1572, 71 L.Ed.2d 783 (1982)); see also Screws v. United States, 325 U.S. 91, 109, 65 S.Ct. 1031, 1039, 89 L.Ed. 1495 (1945) (plurality opinion) ("Our national government is one of delegated powers alone. Under our federal system the administration of criminal justice rests with the States except as Congress, acting within the scope of those delegated powers, has created offenses against the United States"). When Congress criminalizes conduct already denounced as criminal by the States, it effects a " 'change in the sensitive relation between federal and state criminal jurisdiction.' " United States v. Enmons, 410 U.S. 396, 411-412, 93 S.Ct. 1007, 1015- 1016, 35 L.Ed.2d 379 (1973) (quoting United States v. Bass, 404 U.S. 336, 349, 92 S.Ct. 515, 523, 30 L.Ed.2d 488 (1971)). The Government acknowledges that § 922(q) "displace[s] state policy choices in ... that its prohibitions apply even in States that have chosen not to outlaw the conduct in question." Brief for United States 29, n. 18; see also Statement of President George Bush on Signing the Crime Control Act of 1990, 26 Weekly Comp. of Pres. Doc. 1944, 1945 (Nov. 29, 1990) ("Most egregiously, section [922(q)] inappropriately overrides legitimate State firearms laws with a new and unnecessary Federal law. The policies reflected in these provisions could legitimately be adopted by the States, but they should not be imposed upon the States by the Congress").

Second, § 922(q) contains no jurisdictional element which would ensure, through case-by-case inquiry, that the firearm possession in question affects interstate commerce. For example, in United States v. Bass, 404 U.S. 336, 92 S.Ct. 515, 30 L.Ed.2d 488 (1971), the Court interpreted former 18 U.S.C. § 1202(a), which made it a crime for a felon to "receiv[e], posses[s], or transpor[t] in commerce or affecting commerce ... any firearm." 404 U.S., at 337, 92 S.Ct., at 517. The Court interpreted the possession component of § 1202(a) to require an additional nexus to interstate commerce both because the statute was ambiguous and because "unless Congress conveys its purpose clearly, it will not be deemed to have significantly changed the federal-state balance." Id., at 349, 92 S.Ct., at 523. The Bass Court set aside the conviction because, although the Government had demonstrated that Bass had possessed a firearm, it had failed "to show the requisite nexus with interstate commerce." Id., at 347, 92 S.Ct., at 522. The Court thus interpreted the statute to reserve the constitutional question whether Congress could regulate, without more, the "mere possession" of firearms. See id., at 339, n. 4, 92 S.Ct., at 518, n. 4; see also United States v. Five Gambling Devices, 346 U.S. 441, 448, 74 S.Ct. 190, 194, 98 L.Ed. 179 (1953) (plurality opinion) ("The principle is old and deeply imbedded in our jurisprudence that this Court will construe a statute in a manner that requires decision of serious constitutional questions only if the statutory language leaves no reasonable alternative"). Unlike the statute in Bass, § 922(q) has no express jurisdictional element which might limit its reach to a discrete set of firearm possessions that additionally have an explicit connection with or effect on interstate commerce.

Although as part of our independent evaluation of constitutionality under the Commerce Clause we of course consider legislative findings, and indeed even congressional committee findings, regarding effect on interstate commerce, see, e.g., Preseault v. ICC, 494 U.S., at 17, 110 S.Ct., at 924- 925, (1990), the Government concedes that "[n]either the statute nor its legislative history contain[s] express congressional findings regarding the effects upon interstate commerce of gun possession in a school zone." Brief for United States 5-6. We agree with the Government that Congress normally is not required to make formal findings as to the substantial burdens that an activity has on interstate commerce. See McClung, 379 U.S., at 304, 85 S.Ct., at 383-384; see also Perez, 402 U.S., at 156, 91 S.Ct., at 1362 ("Congress need [not] make particularized findings in order to legislate"). But to the extent that congressional findings would enable us to evaluate the legislative judgment that the activity in question substantially affected interstate commerce, even though no such substantial effect was visible to the naked eye, they are lacking here. [FN4]

FN4. We note that on September 13, 1994, President Clinton signed into law the Violent Crime Control and Law Enforcement Act of 1994, Pub.L. 103-322, 108 Stat. 1796. Section 320904 of that Act, id., at 2125, amends § 922(q) to include congressional findings regarding the effects of firearm possession in and around schools upon interstate and foreign commerce. The Government does not rely upon these subsequent findings as a substitute for the absence of findings in the first instance. Tr. of Oral Arg. 25 ("[W]e're not relying on them in the strict sense of the word, but we think that at a very minimum they indicate that reasons can be identified for why Congress wanted to regulate this particular activity").

The Government argues that Congress has accumulated institutional expertise regarding the regulation of firearms through previous enactments. Cf. Fullilove v. Klutznick, 448 U.S. 448, 503, 100 S.Ct. 2758, 2787, 65 L.Ed.2d 902 (1980) (Powell, J., concurring). We agree, however, with the Fifth Circuit that importation of previous findings to justify § 922(q) is especially inappropriate here because the "prior federal enactments or Congressional findings [do not] speak to the subject matter of section 922(q) or its relationship to interstate commerce. Indeed, section 922(q) plows thoroughly new ground and represents a sharp break with the long-standing pattern of federal firearms legislation." 2 F.3d, at 1366.

The Government's essential contention, in fine, is that we may determine here that § 922(q) is valid because possession of a firearm in a local school zone does indeed substantially affect interstate commerce. Brief for United States 17. The Government argues that possession of a firearm in a school zone may result in violent crime and that violent crime can be expected to affect the functioning of the national economy in two ways. First, the costs of violent crime are substantial, and, through the mechanism of insurance, those costs are spread throughout the population. See United States v. Evans, 928 F.2d 858, 862 (CA9 1991). Second, violent crime reduces the willingness of individuals to travel to areas within the country that are perceived to be unsafe. Cf. Heart of Atlanta Motel, 379 U.S., at 253, 85 S.Ct., at 355. The Government also argues that the presence of guns in schools poses a substantial threat to the educational process by threatening the learning environment. A handicapped educational process, in turn, will result in a less productive citizenry. That, in turn, would have an adverse effect on the Nation's economic well-being. As a result, the Government argues that Congress could rationally have concluded that § 922(q) substantially affects interstate commerce.

We pause to consider the implications of the Government's arguments. The Government admits, under its "costs of crime" reasoning, that Congress could regulate not only all violent crime, but all activities that might lead to violent crime, regardless of how tenuously they relate to interstate commerce. See Tr. of Oral Arg. 8-9. Similarly, under the Government's "national productivity" reasoning, Congress could regulate any activity that it found was related to the economic productivity of individual citizens: family law (including marriage, divorce, and child custody), for example. Under the theories that the Government presents in support of § 922(q), it is difficult to perceive any limitation on federal power, even in areas such as criminal law enforcement or education where States historically have been sovereign. Thus, if we were to accept the Government's arguments, we are hard pressed to posit any activity by an individual that Congress is without power to regulate.

Although Justice BREYER argues that acceptance of the Government's rationales would not authorize a general federal police power, he is unable to identify any activity that the States may regulate but Congress may not. Justice BREYER posits that there might be some limitations on Congress' commerce power, such as family law or certain aspects of education. Post, at 1661-1662. These suggested limitations, when viewed in light of the dissent's expansive analysis, are devoid of substance.

Justice BREYER focuses, for the most part, on the threat that firearm possession in and near schools poses to the educational process and the potential economic consequences flowing from that threat. Post, at 1659- 1662. Specifically, the dissent reasons that (1) gun-related violence is a serious problem; (2) that problem, in turn, has an adverse effect on classroom learning; and (3) that adverse effect on classroom learning, in turn, represents a substantial threat to trade and commerce. Post, at 1661. This analysis would be equally applicable, if not more so, to subjects such as family law and direct regulation of education.

For instance, if Congress can, pursuant to its Commerce Clause power, regulate activities that adversely affect the learning environment, then, a fortiori, it also can regulate the educational process directly. Congress could determine that a school's curriculum has a "significant" effect on the extent of classroom learning. As a result, Congress could mandate a federal curriculum for local elementary and secondary schools because what is taught in local schools has a significant "effect on classroom learning," cf. post, at 1661, and that, in turn, has a substantial effect on interstate commerce.

Justice BREYER rejects our reading of precedent and argues that "Congress ... could rationally conclude that schools fall on the commercial side of the line." Post, at 1664. Again, Justice BREYER's rationale lacks any real limits because, depending on the level of generality, any activity can be looked upon as commercial. Under the dissent's rationale, Congress could just as easily look at child rearing as "fall[ing] on the commercial side of the line" because it provides a "valuable service--namely, to equip [children] with the skills they need to survive in life and, more specifically, in the workplace." Ibid. We do not doubt that Congress has authority under the Commerce Clause to regulate numerous commercial activities that substantially affect interstate commerce and also affect the educational process. That authority, though broad, does not include the authority to regulate each and every aspect of local schools.

Admittedly, a determination whether an intrastate activity is commercial or noncommercial may in some cases result in legal uncertainty. But, so long as Congress' authority is limited to those powers enumerated in the Constitution, and so long as those enumerated powers are interpreted as having judicially enforceable outer limits, congressional legislation under the Commerce Clause always will engender "legal uncertainty." Post, at 1664. As Chief Justice Marshall stated in McCulloch v. Maryland, 4 Wheat. 316, 4 L.Ed. 579 (1819):

"Th[e] [federal] government is acknowledged by all to be one of enumerated powers. The principle, that it can exercise only the powers granted to it ... is now universally admitted. But the question respecting the extent of the powers actually granted, is perpetually arising, and will probably continue to arise, as long as our system shall exist." Id., at 405.

See also Gibbons v. Ogden, 9 Wheat., at 195 ("The enumeration presupposes something not enumerated"). The Constitution mandates this uncertainty by withholding from Congress a plenary police power that would authorize enactment of every type of legislation. See Art. I, § 8. Congress has operated within this framework of legal uncertainty ever since this Court determined that it was the Judiciary's duty "to say what the law is." Marbury v. Madison, 1 Cranch 137, 177, 2 L.Ed. 60 (1803) (Marshall, C.J.). Any possible benefit from eliminating this "legal uncertainty" would be at the expense of the Constitution's system of enumerated powers.

In Jones & Laughlin Steel, 301 U.S., at 37, 57 S.Ct., at 624, we held that the question of congressional power under the Commerce Clause "is necessarily one of degree." To the same effect is the concurring opinion of Justice Cardozo in Schechter Poultry:

"There is a view of causation that would obliterate the distinction between what is national and what is local in the activities of commerce. Motion at the outer rim is communicated perceptibly, though minutely, to recording instruments at the center. A society such as ours 'is an elastic medium which transmits all tremors throughout its territory; the only question is of their size.' " 295 U.S., at 554, 55 S.Ct., at 853 (quoting United States v. A.L.A. Schechter Poultry Corp., 76 F.2d 617, 624 (CA2 1935) (L. Hand, J., concurring)).

These are not precise formulations, and in the nature of things they cannot be. But we think they point the way to a correct decision of this case. The possession of a gun in a local school zone is in no sense an economic activity that might, through repetition elsewhere, substantially affect any sort of interstate commerce. Respondent was a local student at a local school; there is no indication that he had recently moved in interstate commerce, and there is no requirement that his possession of the firearm have any concrete tie to interstate commerce.

To uphold the Government's contentions here, we would have to pile inference upon inference in a manner that would bid fair to convert congressional authority under the Commerce Clause to a general police power of the sort retained by the States. Admittedly, some of our prior cases have taken long steps down that road, giving great deference to congressional action. See supra, at 1629. The broad language in these opinions has suggested the possibility of additional expansion, but we decline here to proceed any further. To do so would require us to conclude that the Constitution's enumeration of powers does not presuppose something not enumerated, cf. Gibbons v. Ogden, supra, at 195, and that there never will be a distinction between what is truly national and what is truly local, cf. Jones & Laughlin Steel, supra, at 30, 57 S.Ct., at 621. This we are unwilling to do.

For the foregoing reasons the judgment of the Court of Appeals is

Affirmed.

Justice KENNEDY, with whom Justice O'CONNOR joins, concurring.

The history of the judicial struggle to interpret the Commerce Clause during the transition from the economic system the Founders knew to the single, national market still emergent in our own era counsels great restraint before the Court determines that the Clause is insufficient to support an exercise of the national power. That history gives me some pause about today's decision, but I join the Court's opinion with these observations on what I conceive to be its necessary though limited holding.

Chief Justice Marshall announced that the national authority reaches "that commerce which concerns more States than one" and that the commerce power "is complete in itself, may be exercised to its utmost extent, and acknowledges no limitations, other than are prescribed in the constitution." Gibbons v. Ogden, 9 Wheat. 1, 194, 196, 6 L.Ed. 23 (1824). His statements can be understood now as an early and authoritative recognition that the Commerce Clause grants Congress extensive power and ample discretion to determine its appropriate exercise. The progression of our Commerce Clause cases from Gibbons to the present was not marked, however, by a coherent or consistent course of interpretation; for neither the course of technological advance nor the foundational principles for the jurisprudence itself were self-evident to the courts that sought to resolve contemporary disputes by enduring principles.

Furthermore, for almost a century after the adoption of the Constitution, the Court's Commerce Clause decisions did not concern the authority of Congress to legislate. Rather, the Court faced the related but quite distinct question of the authority of the States to regulate matters that would be within the commerce power had Congress chosen to act. The simple fact was that in the early years of the Republic, Congress seldom perceived the necessity to exercise its power in circumstances where its authority would be called into question. The Court's initial task, therefore, was to elaborate the theories that would permit the States to act where Congress had not done so. Not the least part of the problem was the unresolved question whether the congressional power was exclusive, a question reserved by Chief Justice Marshall in Gibbons v. Ogden, supra, at 209-210.

At the midpoint of the 19th century, the Court embraced the principle that the States and the National Government both have authority to regulate certain matters absent the congressional determination to displace local law or the necessity for the Court to invalidate local law because of the dormant national power. Cooley v. Board of Wardens of Port of Philadelphia, ex rel. Soc. for Relief of Distressed Pilots, 12 How. 299, 318-321, 13 L.Ed. 996 (1852). But the utility of that solution was not at once apparent, see generally F. Frankfurter, The Commerce Clause under Marshall, Taney and Waite (1937) (hereinafter Frankfurter), and difficulties of application persisted, see Leisy v. Hardin, 135 U.S. 100, 122-125, 10 S.Ct. 681, 688-690, 34 L.Ed. 128 (1890).

One approach the Court used to inquire into the lawfulness of state authority was to draw content-based or subject-matter distinctions, thus defining by semantic or formalistic categories those activities that were commerce and those that were not. For instance, in deciding that a State could prohibit the in-state manufacture of liquor intended for out-of-state shipment, it distinguished between manufacture and commerce. "No distinction is more popular to the common mind, or more clearly expressed in economic and political literature, than that between manufactur[e] and commerce. Manufacture is transformation--the fashioning of raw materials into a change of form for use. The functions of commerce are different." Kidd v. Pearson, 128 U.S. 1, 20, 9 S.Ct. 6, 10, 32 L.Ed. 346 (1888). Though that approach likely would not have survived even if confined to the question of a State's authority to enact legislation, it was not at all propitious when applied to the quite different question of what subjects were within the reach of the national power when Congress chose to exercise it.

This became evident when the Court began to confront federal economic regulation enacted in response to the rapid industrial development in the late 19th century. Thus, it relied upon the manufacture-commerce dichotomy in United States v. E.C. Knight Co., 156 U.S. 1, 15 S.Ct. 249, 39 L.Ed. 325 (1895), where a manufacturers' combination controlling some 98% of the Nation's domestic sugar refining capacity was held to be outside the reach of the Sherman Act. Conspiracies to control manufacture, agriculture, mining, production, wages, or prices, the Court explained, had too "indirect" an effect on interstate commerce. Id., at 16, 15 S.Ct., at 255. And in Adair v. United States, 208 U.S. 161, 28 S.Ct. 277, 52 L.Ed. 436 (1908), the Court rejected the view that the commerce power might extend to activities that, although local in the sense of having originated within a single State, nevertheless had a practical effect on interstate commercial activity. The Court concluded that there was not a "legal or logical connection ... between an employé's membership in a labor organization and the carrying on of interstate commerce," id., at 178, 28 S.Ct., at 282, and struck down a federal statute forbidding the discharge of an employee because of his membership in a labor organization. See also The Employers' Liability Cases, 207 U.S. 463, 497, 28 S.Ct. 141, 145, 52 L.Ed. 297 (1908) (invalidating statute creating negligence action against common carriers for personal injuries of employees sustained in the course of employment, because the statute "regulates the persons because they engage in interstate commerce and does not alone regulate the business of interstate commerce").

Even before the Court committed itself to sustaining federal legislation on broad principles of economic practicality, it found it necessary to depart from these decisions. The Court disavowed E.C. Knight 's reliance on the manufacturing-commerce distinction in Standard Oil Co. of N.J. v. United States, 221 U.S. 1, 68-69, 31 S.Ct. 502, 518-519, 55 L.Ed. 619 (1911), declaring that approach "unsound." The Court likewise rejected the rationale of Adair when it decided, in Texas & New Orleans R. Co. v. Railway Clerks, 281 U.S. 548, 570-571, 50 S.Ct. 427, 433-434, 74 L.Ed. 1034 (1930), that Congress had the power to regulate matters pertaining to the organization of railroad workers.

In another line of cases, the Court addressed Congress' efforts to impede local activities it considered undesirable by prohibiting the interstate movement of some essential element. In the Lottery Case, 188 U.S. 321, 23 S.Ct. 321, 47 L.Ed. 492 (1903), the Court rejected the argument that Congress lacked power to prohibit the interstate movement of lottery tickets because it had power only to regulate, not to prohibit. See also Hipolite Egg Co. v. United States, 220 U.S. 45, 31 S.Ct. 364, 55 L.Ed. 364 (1911); Hoke v. United States, 227 U.S. 308, 33 S.Ct. 281, 57 L.Ed. 523 (1913). In Hammer v. Dagenhart, 247 U.S. 251, 38 S.Ct. 529, 62 L.Ed. 1101 (1918), however, the Court insisted that the power to regulate commerce "is directly the contrary of the assumed right to forbid commerce from moving," id., at 269-270, 38 S.Ct., at 530, and struck down a prohibition on the interstate transportation of goods manufactured in violation of child labor laws.

Even while it was experiencing difficulties in finding satisfactory principles in these cases, the Court was pursuing a more sustainable and practical approach in other lines of decisions, particularly those involving the regulation of railroad rates. In the Minnesota Rate Cases, 230 U.S. 352, 33 S.Ct. 729, 57 L.Ed. 1511 (1913), the Court upheld a state rate order, but observed that Congress might be empowered to regulate in this area if "by reason of the interblending of the interstate and intrastate operations of interstate carriers" the regulation of interstate rates could not be maintained without restrictions on "intrastate rates which substantially affect the former." Id., at 432-433, 33 S.Ct., at 753-754. And in the Shreveport Rate Cases, 234 U.S. 342, 34 S.Ct. 833, 58 L.Ed. 1341 (1914), the Court upheld an Interstate Commerce Commission order fixing railroad rates with the explanation that congressional authority, "extending to these interstate carriers as instruments of interstate commerce, necessarily embraces the right to control their operations in all matters having such a close and substantial relation to interstate traffic that the control is essential or appropriate to the security of that traffic, to the efficiency of the interstate service, and to the maintenance of conditions under which interstate commerce may be conducted upon fair terms and without molestation or hindrance." Id., at 351, 34 S.Ct., at 836.

Even the most confined interpretation of "commerce" would embrace transportation between the States, so the rate cases posed much less difficulty for the Court than cases involving manufacture or production. Nevertheless, the Court's recognition of the importance of a practical conception of the commerce power was not altogether confined to the rate cases. In Swift & Co. v. United States, 196 U.S. 375, 25 S.Ct. 276, 49 L.Ed. 518 (1905), the Court upheld the application of federal antitrust law to a combination of meat dealers that occurred in one State but that restrained trade in cattle "sent for sale from a place in one State, with the expectation that they will end their transit ... in another." Id., at 398, 25 S.Ct., at 280. The Court explained that "commerce among the States is not a technical legal conception, but a practical one, drawn from the course of business." Ibid. Chief Justice Taft followed the same approach in upholding federal regulation of stockyards in Stafford v. Wallace, 258 U.S. 495, 42 S.Ct. 397, 66 L.Ed. 735 (1922). Speaking for the Court, he rejected a "nice and technical inquiry," id., at 519, 42 S.Ct., at 403, when the local transactions at issue could not "be separated from the movement to which they contribute," id., at 516, 42 S.Ct., at 402.

Reluctance of the Court to adopt that approach in all of its cases caused inconsistencies in doctrine to persist, however. In addressing New Deal legislation the Court resuscitated the abandoned abstract distinction between direct and indirect effects on interstate commerce. See Carter v. Carter Coal Co., 298 U.S. 238, 309, 56 S.Ct. 855, 872, 80 L.Ed. 1160 (1936) (Act regulating price of coal and wages and hours for miners held to have only "secondary and indirect" effect on interstate commerce); Railroad Retirement Bd. v. Alton R. Co., 295 U.S. 330, 368, 55 S.Ct. 758, 771, 79 L.Ed. 1468 (1935) (compulsory retirement and pension plan for railroad carrier employees too "remote from any regulation of commerce as such"); A.L.A. Schechter Poultry Corp. v. United States, 295 U.S. 495, 548, 55 S.Ct. 837, 851, 79 L.Ed. 1570 (1935) (wage and hour law provision of National Industrial Recovery Act had "no direct relation to interstate commerce").

The case that seems to mark the Court's definitive commitment to the practical conception of the commerce power is NLRB v. Jones & Laughlin Steel Corp., 301 U.S. 1, 57 S.Ct. 615, 81 L.Ed. 893 (1937), where the Court sustained labor laws that applied to manufacturing facilities, making no real attempt to distinguish Carter, supra, and Schechter, supra. 301 U.S., at 40- 41, 57 S.Ct., at 625-626. The deference given to Congress has since been confirmed. United States v. Darby, 312 U.S. 100, 116-117, 61 S.Ct. 451, 458-459, 85 L.Ed. 609 (1941), overruled Hammer v. Dagenhart, supra. And in Wickard v. Filburn, 317 U.S. 111, 63 S.Ct. 82, 87 L.Ed. 122 (1942), the Court disapproved E.C. Knight and the entire line of direct-indirect and manufacture-production cases, explaining that "broader interpretations of the Commerce Clause [were] destined to supersede the earlier ones," at 122, 63 S.Ct., at 88, and "[w]hatever terminology is used, the criterion is necessarily one of degree and must be so defined. This does not satisfy those who seek mathematical or rigid formulas. But such formulas are not provided by the great concepts of the Constitution," id., at 123, n. 24, 63 S.Ct., at 88, n. 24. Later examples of the exercise of federal power where commercial transactions were the subject of regulation include Heart of Atlanta Motel, Inc. v. United States, 379 U.S. 241, 85 S.Ct. 348, 13 L.Ed.2d 258 (1964), Katzenbach v. McClung, 379 U.S. 294, 85 S.Ct. 377, 13 L.Ed.2d 290 (1964), and Perez v. United States, 402 U.S. 146, 91 S.Ct. 1357, 28 L.Ed.2d 686 (1971). These and like authorities are within the fair ambit of the Court's practical conception of commercial regulation and are not called in question by our decision today.

The history of our Commerce Clause decisions contains at least two lessons of relevance to this case. The first, as stated at the outset, is the imprecision of content-based boundaries used without more to define the limits of the Commerce Clause. The second, related to the first but of even greater consequence, is that the Court as an institution and the legal system as a whole have an immense stake in the stability of our Commerce Clause jurisprudence as it has evolved to this point. Stare decisis operates with great force in counseling us not to call in question the essential principles now in place respecting the congressional power to regulate transactions of a commercial nature. That fundamental restraint on our power forecloses us from reverting to an understanding of commerce that would serve only an 18th-century economy, dependent then upon production and trading practices that had changed but little over the preceding centuries; it also mandates against returning to the time when congressional authority to regulate undoubted commercial activities was limited by a judicial determination that those matters had an insufficient connection to an interstate system. Congress can regulate in the commercial sphere on the assumption that we have a single market and a unified purpose to build a stable national economy.

In referring to the whole subject of the federal and state balance, we said this just three Terms ago:

"This framework has been sufficiently flexible over the past two centuries to allow for enormous changes in the nature of government. The Federal Government undertakes activities today that would have been unimaginable to the Framers in two senses: first, because the Framers would not have conceived that any government would conduct such activities; and second, because the Framers would not have believed that the Federal Government, rather than the States, would assume such responsibilities. Yet the powers conferred upon the Federal Government by the Constitution were phrased in language broad enough to allow for the expansion of the Federal Government's role." New York v. United States, 505 U.S. 144, 157, 112 S.Ct. 2408, 2418, 120 L.Ed.2d 120 (1992) (emphasis deleted).

It does not follow, however, that in every instance the Court lacks the authority and responsibility to review congressional attempts to alter the federal balance. This case requires us to consider our place in the design of the Government and to appreciate the significance of federalism in the whole structure of the Constitution.

Of the various structural elements in the Constitution, separation of powers, checks and balances, judicial review, and federalism, only concerning the last does there seem to be much uncertainty respecting the existence, and the content, of standards that allow the Judiciary to play a significant role in maintaining the design contemplated by the Framers. Although the resolution of specific cases has proved difficult, we have derived from the Constitution workable standards to assist in preserving separation of powers and checks and balances. See, e.g., Prize Cases, 2 Black 635, 17 L.Ed. 459 (1863); Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 72 S.Ct. 863, 96 L.Ed. 1153 (1952); United States v. Nixon, 418 U.S. 683, 94 S.Ct. 3090, 41 L.Ed.2d 1039 (1974); Buckley v. Valeo, 424 U.S. 1, 96 S.Ct. 612, 46 L.Ed.2d 659 (1976); INS v. Chadha, 462 U.S. 919, 103 S.Ct. 2764, 77 L.Ed.2d 317 (1983); Bowsher v. Synar, 478 U.S. 714, 106 S.Ct. 3181, 92 L.Ed.2d 583 (1986); Plaut v. Spendthrift Farm, Inc., 514 U.S. 211, 115 S.Ct. 1447, 131 L.Ed.2d 328 (1995). These standards are by now well accepted. Judicial review is also established beyond question, Marbury v. Madison, 1 Cranch 137, 2 L.Ed. 60 (1803), and though we may differ when applying its principles, see, e.g., Planned Parenthood of Southeastern Pa. v. Casey, 505 U.S. 833, 112 S.Ct. 2791, 120 L.Ed.2d 674 (1992), its legitimacy is undoubted. Our role in preserving the federal balance seems more tenuous.

There is irony in this, because of the four structural elements in the Constitution just mentioned, federalism was the unique contribution of the Framers to political science and political theory. See Friendly, Federalism: A Forward, 86 Yale L.J. 1019 (1977); G. Wood, The Creation of the American Republic, 1776-1787, pp. 524-532, 564 (1969). Though on the surface the idea may seem counterintuitive, it was the insight of the Framers that freedom was enhanced by the creation of two governments, not one. "In the compound republic of America, the power surrendered by the people is first divided between two distinct governments, and then the portion allotted to each subdivided among distinct and separate departments. Hence a double security arises to the rights of the people. The different governments will control each other, at the same time that each will be controlled by itself." The Federalist No. 51, p. 323 (C. Rossiter ed. 1961) (J. Madison). See also Gregory v. Ashcroft, 501 U.S. 452, 458-459, 111 S.Ct. 2395, 2400, 115 L.Ed.2d 410 (1991) ("Just as the separation and independence of the coordinate branches of the Federal Government serve to prevent the accumulation of excessive power in any one branch, a healthy balance of power between the States and the Federal Government will reduce the risk of tyranny and abuse from either front.... In the tension between federal and state power lies the promise of liberty"); New York v. United States, supra, at 181, 112 S.Ct., at 2431 ("[T]he Constitution divides authority between federal and state governments for the protection of individuals. State sovereignty is not just an end in itself: 'Rather, federalism secures to citizens the liberties that derive from the diffusion of sovereign power' ") (quoting Coleman v. Thompson, 501 U.S. 722, 759, 111 S.Ct. 2546, 2570, 115 L.Ed.2d 640 (1991).

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