The Massachusetts Board of Retirement v. Murgia case in 1975 revolved around a Massachusetts law that required uniformed state police to retire at the age of 50. Robert Murgia, a state trooper who was forced to retire due to this law, challenged it on grounds that it violated his equal protection rights under the Fourteenth Amendment. The Supreme Court ruled in favor of the Massachusetts Board of Retirement with a vote count of 8-1, stating that while aging is not an entirely accurate predictor for job performance ability, it is still rationally related enough for states to use as a basis for employment decisions such as mandatory retirement ages. Therefore, they concluded that the law did not violate Murgia's equal protection rights.

In the dissenting opinion for Massachusetts Board of Retirement et al. v. Murgia, Justice Marshall argued that the mandatory retirement age of 50 years old for uniformed state police was not rationally related to its stated objective of maintaining a youthful and vigorous police force. He contended that there were other less discriminatory means available to achieve this goal such as physical fitness tests which would be more directly related to an officer's ability to perform his duties than mere chronological age. Furthermore, he pointed out that many officers over 50 are still capable and competent in their roles, thus making the law overly broad and unfair. The justice also criticized the majority’s deferential approach towards legislative classifications involving non-suspect classes or fundamental rights, stating it undermines equal protection guarantees by allowing arbitrary governmental actions based on stereotypes or prejudices.