In the case of United States v. Carlos Dominguez Benitez (2003), the Supreme Court ruled that a defendant who pleads guilty under a plea agreement must show that there is reasonable probability that, but for counsel's errors, he would not have pleaded guilty and would have insisted on going to trial in order to establish prejudice from an error made by his lawyer during the plea process. The court held this standard applies even when a district court fails to inform defendants about certain rights they are waiving by pleading guilty as required under Rule 11 of Federal Rules of Criminal Procedure. In this particular case, Carlos Dominguez Benitez had pled guilty to drug charges without being informed about one aspect of his right against self-incrimination which he could waive through his plea. However, since he failed to demonstrate how knowledge about this right might have affected his decision-making process regarding entering into the plea deal or insisting on going for trial instead, it was concluded that no prejudice resulted from this omission.

In the dissenting opinion for United States v. Carlos Dominguez Benitez, Justice David Souter argued that the majority's decision to apply a harmless-error analysis was incorrect. He contended that Rule 11 of Federal Rules of Criminal Procedure requires courts to inform defendants about any right not to be compelled in any criminal case and if they plead guilty, they waive this right. The failure by the court to provide such information should automatically result in reversal of conviction without requiring defendants to show prejudice or harm from this omission. According to him, it is impossible for a defendant who has not been properly informed about his rights under Rule 11(c)(6) (now renumbered as Rule 11(b)(1)(M)) during plea colloquy could knowingly and voluntarily waive them. Therefore, he disagreed with the majority’s view that there must be proof showing how such an error affected substantial rights before granting relief.