Does the exclusionary rule of search and seizure affect the educational impact of such education?

2 The additional contribution, if any, of the consideration of search-and-seizure claims of state prisoners on collateral review is small in relation to the costs. To be sure, each case in which such claim is considered may add marginally to an awareness of the values protected by the Fourth Amendment. There is no reason to believe, however, that the overall educative effect of the exclusionary rule would be appreciably diminished if search-and-seizure claims could not be raised in federal habeas corpus review of state convictions. Nor is there reason to assume that any specific disincentive already created by the risk of exclusion of evidence at trial or the reversal of convictions on direct review would be enhanced if there were the further risk that a conviction obtained in state court and affirmed on direct review might be overturned in collateral proceedings often occurring years after the incarceration of the defendant. The view that the deterrence of Fourth Amendment violations would be furthered rests on the dubious assumption that law enforcement authorities would fear that federal habeas review might reveal flaws in a search or seizure that went undetected at trial and on appeal. Even if one rationally could assume that some additional incremental deterrent effect would be present in isolated cases, the resulting advance of the legitimate goal of furthering Fourth Amendment rights would be outweighed by the acknowledged costs to other values vital to a rational system of criminal justice.

Stone v. Powell, supra, 428 U.S. at 493-94, 96 S.Ct. at 3051-52 (footnotes omitted).