“ Duncan held that the States must respect the right to jury trial because in the context of the institutions and practices by which we adopt and apply our criminal laws, the right to jury trial generally tends to prevent arbitrariness and repression. As we stated in Duncan, 'We would not assert, however, that every criminal trial-or any particular trial-held before a judge alone is unfair or that a defendant may never be as fairly treated by a judge as he would be by a jury.' 391 U.S., at 158, 88 S.Ct., at 1470. ”

“ The values implemented by the right to jury trial would not measurably be served by requiring retrial of all persons convicted in the past by procedures not consistent with the Sixth Amendment right to jury trial. Second, States undoubtedly relied in good faith upon the past opinions of this Court to the effect that the Sixth Amendment right to jury trial was not applicable to the States. ”

“ One ground for the Bloom result was the belief that contempt trials, which often occur before the very judge who was the object of the allegedly contemptuous behavior, would be more fairly tried if a jury determined guilt. Unlike the judge, the jurymen will not have witnessed or suffered the alleged contempt, nor suggested prosecution for it. However, the tradition of nonjury trials for contempts was more firmly established than the view that States could dispense with jury trial in normal criminal prosecutions, and reliance on the cases overturned by Bloom v. ”