Source: http://supreme.nolo.com/us/425/794/case.html
Timestamp: 2019-04-23 01:05:01+00:00

Document:
Motion by Arizona, purportedly in its proprietary capacity as a consumer of, and as parens patriae for its citizens who consume, electrical energy generated in New Mexico, for leave to file an original complaint in this Court against New Mexico seeking declaratoy and injunctive relief on constitutional grounds against New Mexico's tax on the generation of electricity in that State, is denied. The pending state court action in New Mexico by the Arizona utilities involved in this case raises the same constitutional issues and provides an appropriate forum for litigating such issues.
"On electricity generated inside this state and consumed in this state which was subject to the electrical energy tax, the amount of such tax paid may be credited against the gross receipts tax due this state. [Footnote 3]"
The State of New Mexico concedes [Footnote 4] that the Arizona utilities will not be able to take advantage of the credit because their sales of electrical energy are outside the State ,and that, as to them, the practical effect of New Mexico's statutory scheme is to impose a tax no greater than 4% on the generation of electricity within New Mexico.
Seeking to invoke our original jurisdiction under Art. III, § 2, cls. 1 and 2, of the Constitution and 28 U.S.C. § 1251(a)(1), the State of Arizona has filed a motion for leave to file a bill of complaint in which it asks for declaratory relief that the New Mexico electrical energy tax constitutes an unconstitutional discrimination against and burden upon interstate commerce, denies Arizona citizens due process and equal protection of the laws in violation of the Fourteenth Amendment to the Constitution, and abridges the privileges and immunities guaranteed them by Art. IV, § 2, of the Constitution. The complaint also asks that we enjoin the State of New Mexico from assessing, levying, or collecting the tax imposed by the 1975 Act.
availability of another forum where there is jurisdiction over the named parties, where the issues tendered may be litigated, and where appropriate relief may be had. We incline to a sparing use of our original jurisdiction so that our increasing duties with the appellate docket will not suffer."
"In the exercise of our original jurisdiction so as truly to fulfill the constitutional purpose, we not only must look to the nature of the interest of the complaining State -- the essential quality of the right asserted -- but we must also inquire whether recourse to that jurisdiction . . . is necessary for the State's protection. . . . We have observed that the broad statement that a court having jurisdiction must exercise it . . . is not universally true, but has been qualified in certain cases where the federal courts may, in their discretion, properly withhold the exercise of the jurisdiction conferred upon them where there is no want of another suitable forum."
See also Washington v. General Motors Corp., 406 U. S. 109, 406 U. S. 113-114 (1972).
In the circumstances of this case, we are persuaded that the 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. § 1257(2).
See N.M.Stat.Ann. § 72-16A (Supp. 1975).
N.M.Stat.Ann. § 72-34-1 et seq. (Supp. 1975).
N.M.Stat.Ann. § 72-16A-16.1B (Supp. 1975).
See App. to Brief in Opposition.
* In this connection, it should be noted that the statement quoted from Massachusetts v. Missouri, 308 U. S. 1, 308 U. S. 18-19, referred to the complainant's alternative contention that jurisdiction might be sustained on the theory that a controversy between Massachusetts and the citizens of another State was presented. Under that theory, this Court's jurisdiction would not have been exclusive. See 28 U.S.C. § 1251(b)(3).

References: § 2
 § 1251
 § 2
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 § 1257
 § 72
 § 72
 § 72
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 § 1251