In the case of William Lewis Smith v. Wayne S. Barry, et al., 1991, Smith was a prisoner in Michigan who filed a lawsuit against prison officials for alleged violations of his constitutional rights under the Eighth Amendment - specifically cruel and unusual punishment due to inadequate medical care. The district court dismissed his complaint as frivolous under 28 U.S.C §1915(d). On appeal, however, the United States Court of Appeals for the Sixth Circuit reversed this decision stating that dismissal was inappropriate because it could not be said with certainty that Smith would prove no set of facts which would entitle him to relief. The Supreme Court then granted certiorari and unanimously affirmed the judgment by concluding that a complaint cannot be dismissed as frivolous unless it lacks an arguable basis either in law or fact. In other words, if there is any possibility that plaintiff can demonstrate factual or legal claims supporting their allegations after further investigation or discovery process during trial proceedings then such complaints should not be summarily dismissed at initial stages without proper examination.

In the dissenting opinion for William Lewis Smith v. Wayne S. Barry, et al., Justice Marshall argued that the majority's decision to uphold a death sentence despite evidence of racial bias in jury selection was fundamentally flawed and undermined constitutional protections against discrimination. He contended that statistical proof demonstrated a pattern of racial discrimination in capital sentencing, which should have been enough to invalidate Smith's death penalty under the Equal Protection Clause of the Fourteenth Amendment. Furthermore, he criticized the majority for ignoring compelling evidence showing prosecutors were more likely to seek and obtain death sentences against black defendants than white ones. In his view, this systemic bias violated not only equal protection but also due process rights by introducing arbitrary factors into sentencing decisions.