In the case of Niukkanen, alias Mackie v. McAlexander, Acting District Director, Immigration and Naturalization Service (1959), the U.S Supreme Court ruled on an immigration issue involving a Finnish national who had entered the United States illegally in 1949 under a false name. The individual was later granted permanent residency status but faced deportation after being convicted for crimes related to his illegal entry into the country. He appealed against this decision arguing that he should not be deported because he had been pardoned by President Truman under a general pardon issued in 1952 which covered all offenses committed by aliens entering or attempting to enter unlawfully into America during specific periods including when he entered. The court rejected his argument stating that while presidential pardons can forgive criminal liability they do not erase factual guilt or its consequences unless explicitly stated otherwise; hence it does not prevent deportation based on facts constituting grounds for such action even if those facts are also elements of a pardoned offense. Therefore, despite having received pardon for his crime relating to unlawful entry, Niukkanen could still be deported due to his illegal entrance itself.

In the dissenting opinion for Niukkanen v. McAlexander, it was argued that the majority's decision to deport Niukkanen based on his failure to disclose a previous marriage during his naturalization process was overly harsh and not in line with the intent of immigration laws. The justice contended that while honesty is crucial in these proceedings, minor omissions or inaccuracies should not automatically lead to deportation unless they significantly affect the outcome of an individual’s citizenship application. In this case, Niukkanen's undisclosed first marriage had no bearing on his eligibility for U.S. citizenship as he was divorced before marrying a U.S citizen - which formed part of his claim for naturalization. Therefore, according to this view, stripping him off his acquired citizenship due to such omission seems unjustified and disproportionate punishment.