In the 1991 case of Robert Wayne Sawyer v. John Whitley, Warden, the U.S Supreme Court examined whether a death row inmate's claim that his trial counsel was ineffective could be considered as "cause" for procedural default under federal habeas corpus law. The court ruled in favor of Whitley, stating that Sawyer had not shown cause to excuse his failure to raise this issue at state level. In order to establish cause for procedural default, a petitioner must demonstrate some objective factor external to the defense impeded efforts to comply with state’s procedural rule or show that he received ineffective assistance of counsel at trial or on appeal. The court held that mere attorney error does not qualify as “cause,” and an attorney's ignorance or inadvertence is insufficient reason for failing to follow state procedures.

In the dissenting opinion for Robert Wayne Sawyer v. John Whitley, Warden, Justice Scalia disagreed with the majority's decision to grant habeas corpus relief on grounds of ineffective assistance of counsel during sentencing. He argued that even if there were deficiencies in representation, they did not prejudice the outcome because evidence against Sawyer was overwhelming and his violent character had been clearly established. Furthermore, he criticized the court for creating a new standard for evaluating ineffectiveness claims in capital cases which deviated from precedent set by Strickland v. Washington (1984). This new standard required showing that counsel’s performance undermined confidence in sentence rather than simply affecting its outcome - an approach Scalia found too lenient towards defendants and unfair to states trying to enforce their laws.