In the 1983 case Rushen v. Spain, the U.S. Supreme Court ruled on a matter involving jury impartiality and due process rights of defendants during trial proceedings. The defendant, Jeffrey Allen Spain, was convicted for murder in California state court but later appealed his conviction claiming that he did not receive a fair trial because one juror had engaged in ex parte communications with the judge without his knowledge or consent. These conversations involved her personal experiences related to prison life which she felt might influence her judgment as a juror. The lower courts agreed with Spain's claim and granted him habeas corpus relief (release from detention). However, upon reaching the Supreme Court, it was held that these private discussions did not violate Spain’s constitutional right to be present at all stages of his trial nor did they undermine his right to an impartial jury since there was no evidence showing any actual bias against him by this particular juror or overall prejudice towards him by the entire jury panel.

In the dissenting opinion for Rushen v. Spain, Justice Stevens argued that the majority's decision undermined a defendant's right to be present at all stages of trial and to have counsel present during any communication between judge and juror about the case. He emphasized that these rights are fundamental components of a fair trial as they ensure both parties can respond appropriately to issues raised during deliberations. In this particular case, he noted that ex parte communications occurred between the judge and a juror without notifying defense counsel or allowing them an opportunity to participate in or object to such discussions. This violated due process rights because it prevented full understanding of what transpired during those conversations which could potentially influence jury decisions. Furthermore, he criticized how lower courts handled this issue by not conducting thorough investigations into potential prejudice caused by these interactions before deciding on their harmlessness.