In McPhaul v. United States (1960), the Supreme Court ruled on a case involving contempt of Congress charges against petitioner, Junius Scales. The House Committee on Un-American Activities had subpoenaed Scales to testify and produce documents related to his membership in the Communist Party. When he refused, citing his Fifth Amendment right against self-incrimination, he was charged with contempt of Congress. In a 5-4 decision, the Supreme Court upheld these charges. The majority opinion held that while individuals have a constitutional right not to incriminate themselves during testimony before Congressional committees, this protection does not extend to producing non-testimonial evidence such as records or documents - unless those materials were obtained through illegal means or their authenticity is disputed by the defendant. This ruling clarified that an individual's Fifth Amendment rights do not provide blanket immunity from complying with Congressional subpoenas for document production; rather it depends upon whether providing such material would be testimonial in nature and potentially self-incriminating.

In the dissenting opinion for McPhaul v. United States, Justice Brennan argued that the petitioner's conviction should be overturned because he was not given a fair opportunity to challenge the constitutionality of his indictment before trial. He contended that due process requires an accused person to have this opportunity and criticized the majority for failing to address this issue in their decision. Furthermore, Justice Brennan disagreed with the majority's interpretation of Rule 42(b) of Federal Rules of Criminal Procedure which allows summary punishment for contempt committed in court presence. He believed it did not apply as McPhaul’s actions were outside courtroom proceedings and hence deserved notice and hearing under Rule 42(a). Lastly, he expressed concern over potential abuse by committee chairmen who might use their power arbitrarily against witnesses they dislike or disagree with.