In the case of Ellis Gregory, Jr. and Anthony P. Nugent, Jr., Judges v. John D. Ashcroft, Governor of Missouri (1990), the U.S Supreme Court was tasked with determining whether a Missouri statute that required nonpartisan court plan judges to retire at age 70 violated the Equal Protection Clause or Due Process Clause of the Fourteenth Amendment. The plaintiffs were two judges who had been forced into retirement due to their age under this law and argued that it was discriminatory based on age without serving any substantial state interest. The Supreme Court ruled in favor of Governor Ashcroft upholding the constitutionality of mandatory retirement ages for judges as they did not violate either clause mentioned above from Fourteenth Amendment rights. The court reasoned that such laws serve legitimate state interests including preserving integrity and competency within judiciary system by ensuring mental acuity among its members which can decline with advancing years.

In the dissenting opinion for Ellis Gregory, Jr. and Anthony P. Nugent, Jr., Judges v. John D. Ashcroft, Governor of Missouri (1990), Justice Marshall argued that the majority's decision was a departure from established precedent regarding judicial independence and impartiality in state courts under the Fourteenth Amendment's Due Process Clause. He contended that by upholding Missouri’s nonpartisan court plan - which allowed sitting judges to be removed through retention elections without any allegations or proof of misconduct - it undermined these principles as it subjected judges to political pressures and potential retaliation from displeased litigants or politicians who could influence their re-election outcomes based on unpopular decisions rather than their qualifications or integrity. Furthermore, he criticized the majority for failing to apply strict scrutiny review given that this case involved fundamental rights related to due process protections against arbitrary government action.