In the 1990 U.S. Supreme Court case James A. Ford v. Georgia, the court examined whether a change in law could be applied retroactively to an ongoing legal proceeding. The defendant, James A. Ford, was convicted of murder and sentenced to death by a jury that had been selected using peremptory challenges - a practice allowing attorneys to reject potential jurors without stating a reason which was later deemed unconstitutional if used for racial discrimination (Batson v Kentucky). After his conviction but before his appeal process ended, this new ruling came into effect; however, the Georgia courts denied him relief on grounds that he failed to object at trial as required under state procedural rules. The Supreme Court ruled in favor of Ford with Justice Thurgood Marshall writing for majority opinion stating that it would be fundamentally unfair not to apply Batson's rule retroactively since it constituted "a clear break" from previous law and because its purpose was designed specifically against discriminatory practices during jury selection process.

In the dissenting opinion for James A. Ford v. Georgia, Justice Thurgood Marshall argued that the majority's decision was a misinterpretation of the law and an injustice to Ford. He contended that it was unfair to apply new rules retroactively, especially when they could potentially affect a defendant’s right to fair trial or sentencing process. In his view, this case should have been evaluated based on the legal standards at the time of Ford's original trial rather than current ones which were established after his conviction and sentence had already taken place. Furthermore, he disagreed with majority’s assertion that there wasn’t enough evidence showing racial bias in jury selection during Ford’s trial; instead he believed such bias did exist but was overlooked by courts due to procedural errors made by defense counsel during appeal process.