Mr. Justice Stewart
delivered the opinion of the Court.
New Mexico has imposed a tax on the privilege of generating electricity within its borders. The question in this case is whether that tax conflicts with federal law, statutory or constitutional.
I
The Four Corners power plants, located in New Mexico’s desert northwest, are owned by the appellants, five public utilities companies.1 Most of the electricity generated at the plants is ultimately sold to out-of-state consumers.2 New [143]*143Mexico imposes a 4% gross receipts tax on retail sellers of electricity,3 but since the bulk of the appellants' sales are made to consumers in other States, they do not incur significant liability for this tax. In 1975, New Mexico enacted the Electrical Energy Tax Act, the law at issue in this case.4 That Act imposes a tax on the privilege of generating electricity at the rate of %o of a mill on each net kilowatt hour of electricity generated. This is roughly equivalent to a tax on the retail value of the electricity. The tax is imposed on all companies generating electricity within the State. Section 9 of the Act, however, provides that this electrical energy tax may be fully credited against the company’s gross receipts tax liability.
The Act and the regulations implementing it insure that the electrical generating company will receive full credit for the [144]*144tax even if it does not itself make retail sales of electricity. This result is accomplished by requiring the generating company to assign its “potential credit” to the retailer, who in turn is required to reimburse the generating company for the value of this credit.5 The consequence is that a generating [145]*145company’s 2% tax is completely offset by the credit against the 4% retail sales tax when its electricity is sold within New Mexico. But to the extent that the electricity generated in New Mexico is not sold at retail in the State, there is no gross receipts tax liability against which to offset the electrical energy tax liability of the generating company.
In 1976, the State of Arizona, as a consumer of electricity and parens patriae for its citizens, sought to invoke this Court’s original jurisdiction by a motion for leave to file a bill of complaint against New Mexico, asking for a declaratory judgment invalidating this New Mexico tax. The litigation now before us had already been initiated in the New Mexico courts by the present appellants, seeking essentially the same relief. This Court denied Arizona leave to file its complaint, concluding:
“[T]he pending state-court action provides an appropriate forum in which the issues tendered here may be litigated. If on appeal the New Mexico Supreme Court should hold the electrical energy tax unconstitutional, Arizona will have been vindicated. If, on the other hand, the tax is held to be constitutional, the issues raised now may be brought to this Court by way of direct appeal under 28 U. S. C. § 1267 (2).” Arizona v. New Mexico, 425 U. S. 794, 797.
One of the alternative scenarios foreseen in our 1976 opinion has now eventuated. The New Mexico Supreme Court has upheld the validity of this energy tax against federal statutory and constitutional attacks, Arizona Public Serv. Co. v. O’Chesky, 91 N. M. 485, 576 P. 2d 291, and the issues have been brought to this Court by way of direct appeal under 28 U. S. C. § 1257 (2). 439 U. S. 891.
[146]*146II
The appellants contend that the New Mexico tax is invalid under a specific federal statute as well as under the Commerce, Due Process, and Import-Export Clauses of the Constitution. Because we conclude that under the Supremacy Clause 6 the tax is invalid by reason of this federal statute, we do not reach the substantive constitutional issues.
When Congress enacted the Tax Reform Act of 1976 it included a provision relating to state taxes on electricity. Section 2121 (a) of the Act, 90 Stat. 1914, codified at 16 U. S. C. § 391, provides:
“No State, or political subdivision thereof, may impose or assess a tax on or with respect to the generation or transmission of electricity which discriminates against out-of-State manufacturers, producers, wholesalers, retailers, or consumers of that electricity. For purposes of this section, a tax is discriminatory if it results, either directly or indirectly, in a greater tax burden on electricity which is generated and transmitted in interstate commerce than on electricity which is generated and transmitted in intrastate commerce.”
This provision was not in the bill as passed by the House of Representatives. Its genesis was in the Senate Finance Committee, although in its original version the definition of a discriminatory tax was different from that in the law finally enacted:
“For purposes of this section a tax is discriminatory that either directly or indirectly results in the payment of a higher gross or net tax on electricity which is generated and transmitted in interstate commerce than on elec[147]*147tricity which is generated and transmitted in intrastate commerce.” H. R. 10612, 94th Cong., 1st Sess., § 1323 (1976).
The Committee's Report described the reasons for including the provision:
“The committee has learned that one State places a discriminatory tax upon the production of electricity within its boundaries for consumption outside its boundaries. While the rate of the tax itself is identical for electricity that is ultimately consumed outside the State and electricity which is consumed inside the State, discrimination results because the State allows the amount of the tax to be credited against its gross receipts tax if the electricity is consumed within its boundaries. This credit normally benefits only domiciliarles of the taxing State since no credit is allowed for electricity produced within the State and consumed outside the State. As a result, the cost of the electricity to nondomiciliaries is normally increased by the cost the producer of the electricity must bear in paying the tax. However, the cost to domiciliaries of the taxing State does not include the amount of the tax.
“The committee believes that this is an example of discriminatory State taxation which is properly within the ability of Congress to prohibit through its power to regulate interstate commerce.” (Footnote omitted.) S. Rep. No. 9<R938, pt. I, pp. 437-438 (1976).
The identity of the unnamed State was disclosed during the course of a subsequent Senate floor debate on a motion by Senator Domenici of New Mexico to strike the provision from the bill. Senators Domenici and Montoya of New Mexico, Senators Fannin and Goldwater of Arizona, and Senator Cranston of California made it clear that the provision was aimed directly at New Mexico’s electrical energy tax.
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Mr. Justice Stewart
delivered the opinion of the Court.
New Mexico has imposed a tax on the privilege of generating electricity within its borders. The question in this case is whether that tax conflicts with federal law, statutory or constitutional.
I
The Four Corners power plants, located in New Mexico’s desert northwest, are owned by the appellants, five public utilities companies.1 Most of the electricity generated at the plants is ultimately sold to out-of-state consumers.2 New [143]*143Mexico imposes a 4% gross receipts tax on retail sellers of electricity,3 but since the bulk of the appellants' sales are made to consumers in other States, they do not incur significant liability for this tax. In 1975, New Mexico enacted the Electrical Energy Tax Act, the law at issue in this case.4 That Act imposes a tax on the privilege of generating electricity at the rate of %o of a mill on each net kilowatt hour of electricity generated. This is roughly equivalent to a tax on the retail value of the electricity. The tax is imposed on all companies generating electricity within the State. Section 9 of the Act, however, provides that this electrical energy tax may be fully credited against the company’s gross receipts tax liability.
The Act and the regulations implementing it insure that the electrical generating company will receive full credit for the [144]*144tax even if it does not itself make retail sales of electricity. This result is accomplished by requiring the generating company to assign its “potential credit” to the retailer, who in turn is required to reimburse the generating company for the value of this credit.5 The consequence is that a generating [145]*145company’s 2% tax is completely offset by the credit against the 4% retail sales tax when its electricity is sold within New Mexico. But to the extent that the electricity generated in New Mexico is not sold at retail in the State, there is no gross receipts tax liability against which to offset the electrical energy tax liability of the generating company.
In 1976, the State of Arizona, as a consumer of electricity and parens patriae for its citizens, sought to invoke this Court’s original jurisdiction by a motion for leave to file a bill of complaint against New Mexico, asking for a declaratory judgment invalidating this New Mexico tax. The litigation now before us had already been initiated in the New Mexico courts by the present appellants, seeking essentially the same relief. This Court denied Arizona leave to file its complaint, concluding:
“[T]he pending state-court action provides an appropriate forum in which the issues tendered here may be litigated. If on appeal the New Mexico Supreme Court should hold the electrical energy tax unconstitutional, Arizona will have been vindicated. If, on the other hand, the tax is held to be constitutional, the issues raised now may be brought to this Court by way of direct appeal under 28 U. S. C. § 1267 (2).” Arizona v. New Mexico, 425 U. S. 794, 797.
One of the alternative scenarios foreseen in our 1976 opinion has now eventuated. The New Mexico Supreme Court has upheld the validity of this energy tax against federal statutory and constitutional attacks, Arizona Public Serv. Co. v. O’Chesky, 91 N. M. 485, 576 P. 2d 291, and the issues have been brought to this Court by way of direct appeal under 28 U. S. C. § 1257 (2). 439 U. S. 891.
[146]*146II
The appellants contend that the New Mexico tax is invalid under a specific federal statute as well as under the Commerce, Due Process, and Import-Export Clauses of the Constitution. Because we conclude that under the Supremacy Clause 6 the tax is invalid by reason of this federal statute, we do not reach the substantive constitutional issues.
When Congress enacted the Tax Reform Act of 1976 it included a provision relating to state taxes on electricity. Section 2121 (a) of the Act, 90 Stat. 1914, codified at 16 U. S. C. § 391, provides:
“No State, or political subdivision thereof, may impose or assess a tax on or with respect to the generation or transmission of electricity which discriminates against out-of-State manufacturers, producers, wholesalers, retailers, or consumers of that electricity. For purposes of this section, a tax is discriminatory if it results, either directly or indirectly, in a greater tax burden on electricity which is generated and transmitted in interstate commerce than on electricity which is generated and transmitted in intrastate commerce.”
This provision was not in the bill as passed by the House of Representatives. Its genesis was in the Senate Finance Committee, although in its original version the definition of a discriminatory tax was different from that in the law finally enacted:
“For purposes of this section a tax is discriminatory that either directly or indirectly results in the payment of a higher gross or net tax on electricity which is generated and transmitted in interstate commerce than on elec[147]*147tricity which is generated and transmitted in intrastate commerce.” H. R. 10612, 94th Cong., 1st Sess., § 1323 (1976).
The Committee's Report described the reasons for including the provision:
“The committee has learned that one State places a discriminatory tax upon the production of electricity within its boundaries for consumption outside its boundaries. While the rate of the tax itself is identical for electricity that is ultimately consumed outside the State and electricity which is consumed inside the State, discrimination results because the State allows the amount of the tax to be credited against its gross receipts tax if the electricity is consumed within its boundaries. This credit normally benefits only domiciliarles of the taxing State since no credit is allowed for electricity produced within the State and consumed outside the State. As a result, the cost of the electricity to nondomiciliaries is normally increased by the cost the producer of the electricity must bear in paying the tax. However, the cost to domiciliaries of the taxing State does not include the amount of the tax.
“The committee believes that this is an example of discriminatory State taxation which is properly within the ability of Congress to prohibit through its power to regulate interstate commerce.” (Footnote omitted.) S. Rep. No. 9<R938, pt. I, pp. 437-438 (1976).
The identity of the unnamed State was disclosed during the course of a subsequent Senate floor debate on a motion by Senator Domenici of New Mexico to strike the provision from the bill. Senators Domenici and Montoya of New Mexico, Senators Fannin and Goldwater of Arizona, and Senator Cranston of California made it clear that the provision was aimed directly at New Mexico’s electrical energy tax. 122 [148]*148Cong. Rec. 24324-24329 (1976). At the conclusion of this debate, Senator Domenici’s motion to eliminate the provision was defeated. Id., at 24329.
The appellees concede that this statutory provision was aimed directly at the New Mexico Electrical Energy Tax Act. They contend, however, that the definition of a discriminatory tax was so defused in the Conference Committee that Congress in the law as enacted failed to hit its mark. Specifically, they point out that a discriminatory tax, defined in the Senate Committee’s original draft as one that results in “the payment of a higher gross or net tax,” became in the statute as enacted one which results in “a greater tax burden” on electricity transmitted out of state than that sold within the State.
We are told that the statutory definition was redrafted in the Conference Committee to allay the concerns of Senators from States with somewhat similar taxes. That Committee’s Report gave no reason, however, for the change in language. The Report merely stated:
“Senate amendment. — Under present law, any restrictions on the power of States or their political subdivisions to tax goods or services produced in the taxing State for nondomiciliary use outside the taxing State are derived from court interpretations of the interstate commerce clause of the Constitution.
“The Senate amendment prohibits any State or political subdivision of a State from directly or indirectly imposing any tax on the generation or transmission of electricity which discriminates against out-of-State users. This provision is effective for taxable years beginning after June 30, 1974.
“Conference agreement. — The conference agreement follows the Senate amendment.” H. R. Conf. Rep. No. 94M515, p. 503 (1976).
There is thus no legislative history to show what the Conference Committee’s drafting change was intended to accom[149]*149plish. But the provision as enacted is far from the “sterile” legislation that the appellees contend it is. To the contrary, the provision clearly operates, we think, to carry out the expressed intent of the Senate to invalidate the New Mexico tax.
The Act prohibits “a tax on or with respect to the generation or transmission of electricity” which “results, either directly or indirectly, in a greater tax burden on electricity” consumed outside of New Mexico than that consumed in the State. The appellees urge that this statutory provision is no more than a prohibition of a tax that is invalid under the constitutional test of the Commerce Clause. That test, they say, requires examination of New Mexico’s total tax structure to determine whether the State in fact imposes a greater tax burden on electricity sent out of state. See Halliburton Oil Well Cementing Co. v. Reily, 373 U. S. 64, 69. And the tax in question, they say, clearly survives such an examination. Power sold within New Mexico, they argue, is subject to a 4% tax: 2% from the electrical energy tax and 2% from the gross receipts tax. By contrast, New Mexico subjects electricity sent out of state only to its 2% generation tax. The appellees contend, therefore, that if there is any discrimination in New Mexico’s taxing structure, it is discrimination against electricity consumed within the State.
But, whatever the validity may be of the Commerce Clause test advanced by the appellees, the federal statutory provision is directed specifically at a state tax “on or with respect to the generation or transmission of electricity,” not to the entire tax structure of the State. The tax imposed by New Mexico’s Electrical Energy Tax Act is concededly a tax on the generation of electricity. The tax-credit provisions of the Act itself insure that locally consumed electricity is subject to no tax burden from the electrical energy tax, while the bulk of the electricity generated in New Mexico by the appellants is subject to a 2% tax, since it is sold outside the State. To look [150]*150narrowly to the type of tax the federal statute names, rather than to consider the entire tax structure of the State, is to be faithful not only to the language of that statute but also to the expressed intent of Congress in enacting it. Because the electrical energy tax itself indirectly but necessarily discriminates against electricity sold outside New Mexico, it violates the federal statute.7
The appellees also argue that if the federal statute is construed to invalidate the New Mexico tax, it exceeds the permissible bounds of congressional action under the Commerce Clause. In view of the broad power of Congress to regulate interstate commerce, this argument must be rejected. See Wickard v. Filburn, 317 U. S. 111; Katzenbach v. McClung, 379 U. S. 294. Here, the Congress had a rational basis for finding that the New Mexico tax interfered with interstate commerce, and selected a reasonable method to eliminate that interference. The legislation thus, was within the constitutional power of Congress to enact. See Heart of Atlanta Motel, Inc. v. United States, 379 U. S. 241, 258-259; United States v. Wrightwood Dairy Co., 315 U. S. 110, 119.
The generation of electricity in the Four Corners region undoubtedly also generates environmental and other problems for New Mexico. There is no indication that Congress intended to prevent the State from taxing the generation of [151]*151electricity to pay for solutions to these problems. But the generation of electricity to be sent to Phoenix causes no more problems than the generation of electricity to be sent to Albuquerque. Congress required only that New Mexico, if it chooses to tax the generation of electricity for consumption in either city, tax it equally for each.
The judgment is reversed.
It is so ordered.