Davis v. South Carolina was a United States Supreme Court case that dealt with the issue of whether a state could impose a poll tax on its citizens. The case was brought by a South Carolina resident, William Davis, who argued that the state's poll tax was unconstitutional. The Supreme Court ultimately ruled in favor of Davis, finding that the poll tax was a violation of the Fourteenth Amendment's Equal Protection Clause. The Court reasoned that the poll tax was a form of taxation that was based on a person's ability to pay, rather than on their ability to vote. This meant that the tax was not based on any rational basis, and thus violated the Equal Protection Clause. The Court also noted that the poll tax was a form of taxation that disproportionately affected the poor, and thus violated the Equal Protection Clause's guarantee of equal protection under the law. In its ruling, the Court held that the poll tax was unconstitutional and that the state of South Carolina could not impose it on its citizens. This ruling was a major victory for civil rights activists, as it helped to ensure that all citizens had equal access to the ballot box.

Justice Field delivered the dissenting opinion in Davis v. South Carolina, arguing that the state of South Carolina had violated the Fourteenth Amendment by denying African American citizens their right to vote. He argued that while states have a broad power to regulate elections, they cannot deny any citizen from voting on account of race or color. Justice Field noted that although there were other qualifications for voting such as literacy and property ownership, these qualifications could not be used to discriminate against certain classes of people based on race or color. Furthermore, he argued that if states are allowed to impose additional restrictions beyond those enumerated in the Constitution then it would lead to unequal protection under law and deprive individuals of their rights without due process. In conclusion, Justice Field asserted that since African Americans were denied their right to vote solely because of their race or color this was an unconstitutional violation which should be overturned by the Supreme Court.