What allowed people to vote even if they could not pass the literacy test if their grandfathers or fathers had voted?

The practice that allowed individuals to vote despite failing literacy tests was known as the "grandfather clause." This clause permitted those whose grandfathers or fathers had been eligible to vote before a certain date to bypass literacy tests and other voting requirements. It effectively exempted many white voters from these tests while disenfranchising Black voters and others, thereby upholding systemic racism in the electoral process. Grandfather clauses were implemented in several Southern states as part of broader Jim Crow laws to maintain white supremacy in voting.