A poll tax is a fixed sum required to be paid in order to vote. It was highly controversial because it disproportionately affected low-income and minority voters, effectively disenfranchising them. Aimed at maintaining political control in the post-Reconstruction era, the tax was eventually declared unconstitutional by the 24th Amendment in 1964 and later reaffirmed by the Supreme Court in 1966. This highlighted issues of voter suppression and inequality in the electoral process, leading to significant debate over civil rights and access to democracy.