What follows is an opinion from the Supreme Court of the United States. Your task is to determine the bases on which the Supreme Court rested its decision with regard to the legal provision that the Court considered in the case. Consider "judicial review (national level)" if the majority determined the constitutionality of some action taken by some unit or official of the federal government, including an interstate compact. Consider "judicial review (state level)" if the majority determined the constitutionality of some action taken by some unit or official of a state or local government. Consider "statutory construction" for cases where the majority interpret a federal statute, treaty, or court rule; if the Court interprets a federal statute governing the powers or jurisdiction of a federal court; if the Court construes a state law as incompatible with a federal law; or if an administrative official interprets a federal statute. Do not consider "statutory construction" where an administrative agency or official acts "pursuant to" a statute, unless the Court interprets the statute to determine if administrative action is proper. Consider "interpretation of administrative regulation or rule, or executive order" if the majority treats federal administrative action in arriving at its decision.Consider "diversity jurisdiction" if the majority said in approximately so many words that under its diversity jurisdiction it is interpreting state law. Consider "federal common law" if the majority indicate that it used a judge-made "doctrine" or "rule; if the Court without more merely specifies the disposition the Court has made of the case and cites one or more of its own previously decided cases unless the citation is qualified by the word "see."; if the case concerns admiralty or maritime law, or some other aspect of the law of nations other than a treaty; if the case concerns the retroactive application of a constitutional provision or a previous decision of the Court; if the case concerns an exclusionary rule, the harmless error rule (though not the statute), the abstention doctrine, comity, res judicata, or collateral estoppel; or if the case concerns a "rule" or "doctrine" that is not specified as related to or connected with a constitutional or statutory provision. Consider "Supreme Court supervision of lower federal or state courts or original jurisdiction" otherwise (i.e., the residual code); for issues pertaining to non-statutorily based Judicial Power topics; for cases arising under the Court's original jurisdiction; in cases in which the Court denied or dismissed the petition for review or where the decision of a lower court is affirmed by a tie vote; or in workers' compensation litigation involving statutory interpretation and, in addition, a discussion of jury determination and/or the sufficiency of the evidence.

Opinion:
ELLIS v. UNITED STATES.
No. 293,
Misc.
Decided May 26, 1958.
Kingdon Gould, Jr. for petitioner.
Solicitor General Rankin, Acting Assistant Attorney General McLean and Beatrice Rosenberg for the United States.
Per Curiam.
The petition for writ of certiorari is granted, as is leave to proceed in forma pauperis.
The Court of Appeals denied petitioner leave to appeal in forma pauperis a conviction for housebreaking and larceny. 101 U. S. App. D. C. 386, 249 F. 2d 478. The Solicitor General concedes that leave to appeal should have been allowed unless petitioner’s contentions on the merits were frivolous. The only statutory requirement for the allowance of an indigent’s appeal is the applicant’s “good faith.” 28 U. S. C. § 1915. In the absence of some evident improper motive, the applicant’s good faith is established by the presentation of any issue that is not plainly frivolous. Farley v. United States, 354 U. S. 521. The good-faith test must not be converted into a requirement of a preliminary showing of any particular degree of merit. Unless the issues raised are so frivolous that the appeal would be dismissed in the case of a nonindigent litigant, Fed. Rules Crim. Proc. 39 (a), the request of an indigent for leave to appeal in forma pauperis must be allowed.
Normally, allowance of an appeal should not be denied until an indigent has had adequate representation by counsel. Johnson v. United States, 352 U. S. 565. In this case, it appears that the two attorneys appointed by the Court of Appeals, performed essentially the role of amici curiae. But representation in the role of an advocate is required.. If counsel is convinced, after conscientious investigation, that the appeal is frivolous, of course, he may ask to withdraw on that account. If the court is satisfied that counsel has diligently investigated the possible grounds of appeal, and agrees with counsel’s evaluation of the case, then leave to withdraw may be allowed and leave to appeal may be denied. In this case, the Solicitor General concedes, and after examining the record we agree, that the issue presented — probable cause to arrest — is not one that “can necessarily be characterized as frivolous.” Accordingly, the judgment of the Court of Appeals is vacated, and the case is remanded for reconsideration in light of this opinion.

Question: What is the basis of the Supreme Court's decision?

Choices:
judicial review (national level)
judicial review (state level)
Supreme Court supervision of lower federal or state courts or original jurisdiction
statutory construction
interpretation of administrative regulation or rule, or executive order
diversity jurisdiction
federal common law

Answer: 2