In the case of Tate v. Short in 1970, the U.S. Supreme Court ruled that it was unconstitutional to convert unpaid fines into jail time when an individual is unable to pay due to indigency. The appellant, Preston Tate, had been fined $425 for traffic offenses and sentenced to a term of imprisonment because he could not afford his fine. He argued this violated the Equal Protection Clause of the Fourteenth Amendment as it discriminated against those who are poor by punishing them more severely than those with means simply because they cannot pay their fines immediately upon sentencing. The court agreed with him unanimously (8-0), stating that imprisoning someone solely because they can't afford a fine creates a "criminal process that treats defendants differently based on their wealth," which is fundamentally unfair and violates equal protection under law.

In the dissenting opinion for Tate v. Short, Justice Black expressed his belief that there was no constitutional violation in imprisoning an individual who could not afford to pay a fine. He argued that the Equal Protection Clause does not require states to tailor their penal systems to accommodate individuals' financial circumstances and suggested that such a requirement would be impractical and potentially detrimental to law enforcement efforts. Furthermore, he contended that imprisonment is often used as a last resort when other methods of punishment have failed or are inappropriate, implying it may sometimes be necessary regardless of one's ability to pay fines. In essence, Justice Black disagreed with the majority's interpretation of equal protection under the Fourteenth Amendment in this context.