In the case of Lassiter v. Northampton County Board of Elections, 1958, the U.S Supreme Court ruled on a challenge to literacy tests as a prerequisite for voting in North Carolina. The plaintiff, Lena Lassiter, argued that these tests were discriminatory and violated her rights under the Fourteenth Amendment's Equal Protection Clause. However, the court upheld their constitutionality by a vote of 6-3. The majority opinion held that while literacy tests could potentially be used discriminatorily against certain racial or ethnic groups (as had been historically true in many Southern states), there was no evidence presented in this particular case to suggest such discrimination was occurring in North Carolina at that time. Therefore, they concluded it was not inherently unconstitutional for states to require voters demonstrate some basic level of literacy before being allowed to cast ballots.

In the dissenting opinion for Lassiter v. Northampton County Board of Elections, Justice Hugo Black argued that literacy tests as a prerequisite to vote were unconstitutional and violated the Fifteenth Amendment. He contended that such tests could be manipulated easily by those in power to disenfranchise certain groups based on race or color, which was against the spirit of equal protection under law guaranteed by the Constitution. Furthermore, he believed that voting is a fundamental right for every citizen regardless of their educational attainment or literacy level; thus any barrier placed on this right should be subjected to strict scrutiny. The majority's decision upholding these tests was seen as an endorsement of discriminatory practices and inconsistent with democratic principles.