concurring.
While I join the Court’s entire opinion, I add this caveat concerning the discussion in Part II of respondent’s standing to challenge his arrest on federal constitutional grounds. If we had concluded that he did not have standing as a matter of federal law, the question that would then have been presented would be whether this Court simply should have dismissed the appeal. For we have no power to prevent state courts from allowing litigants to raise federal questions even though they would not have standing to do so in a federal court. See Secretary of State of Maryland v. Joseph H. Munson Co., 467 U. S. 947, 970-971 (1984) (concurring opinion).
Questions of that kind buttress my opinion that the Court grants review in far too many cases in which state courts have protected the constitutional rights of their own citizens. Notwithstanding the Court’s decision to enlarge its *102own power to review state-court judgments, see Michigan v. Long, 463 U. S. 1032 (1983), I remain convinced that this power should be used sparingly. See generally Delaware v. Van Arsdall, 475 U. S. 673, 689-708 (1986) (dissenting opinion). Only in the most unusual case should the Court volunteer its opinion that a state court has imposed standards upon its own law enforcement officials that are too high.