“ The Board of Dentistry seeks certiorari, contending that the Court of Appeals assumed appellate jurisdiction over the courts of the State of Florida and violated doctrines of res judicata in deciding an issue-the fundamental fairness of the hearing held by the Board-which had already been decided adversely to Mack in the state courts. ”

“ Dade County, 419 F.2d 10 (CA5 1969) , holding that a federal court may not determine constitutional issues already submitted to and determined by a state court. Indeed, Angel v. Bullington, 330 U.S. 183, 67 S.Ct. 657, 91 L.Ed. 832 (1947) , which the Board does not cite, indicates that a federal court may not even decide issues which could have been but were not submitted to a state court in prior litigation.
The issue raised by petitioner is not, however, without difficulty and confusion. ”

“ It has also been urged that a federal court should ignore the usual rules of res judicata when a plaintiff, who was a defendant in state court proceedings and who was thus compelled initially to present his federal claims in a state court, seeks in a federal suit to vindicate a specially protected federal interest. See Note, 53 Va.L.Rev. 1360 (1967) .
Whether § 1983 is to serve as the analogue to habeas corpus in civil cases displacing the usual rules of finality seems an important and timely issue having serious statefederal implications. Cf. Younger v. ”