In the case of Humberto Fernandez-Vargas v. Alberto R. Gonzales, Attorney General, 2005, the U.S Supreme Court ruled that a law passed in 1996 could be applied retroactively to immigrants who had returned to the United States after being deported. The petitioner, Humberto Fernandez-Vargas was an illegal immigrant from Mexico who had been deported multiple times but kept returning and eventually married a U.S citizen and started a business in Utah. When he tried to adjust his status based on his marriage, he was ordered for removal under the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) of 1996 which penalizes reentry after deportation without special permission. He argued that applying this law retroactively violated due process clause as it wasn't in effect when he last entered into US illegally before its enactment . However,the court disagreed with him stating that Congress intended IIRIRA's provisions to apply retrospectively and found no constitutional issue with doing so.

In the dissenting opinion for Humberto Fernandez-Vargas v. Alberto R. Gonzales, Justice Stevens argued that the majority's interpretation of the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) was flawed because it retroactively punished conduct that occurred before its enactment in 1996. He contended that this violated a fundamental principle of justice - individuals should have an opportunity to know what the law is and conform their conduct accordingly. Furthermore, he criticized the majority’s reliance on administrative convenience as justification for applying IIRIRA retroactively, arguing instead that fairness considerations should prevail over such concerns when interpreting ambiguous statutes with potential retrospective effects. Finally, Justice Stevens emphasized his belief in respecting settled expectations by not imposing new legal consequences on past actions without clear legislative intent.