Final answer:
The Twenty-Fourth Amendment to the U.S. Constitution prohibits the usage of poll taxes as a condition for voting in federal elections, ensuring that the right to vote cannot be denied by the inability to pay such a tax. The Harper v. Virginia Board of Elections Supreme Court case in 1966 further extended this prohibition to state elections.
Step-by-step explanation:
The Twenty-Fourth Amendment was a critical part of United States constitutional law that aimed to further secure the voting rights of citizens by eliminating barriers to participate in elections. Specifically, this amendment states that the right to vote in any primary or other election for President, Vice President, Senator, or Representative in Congress shall not be denied or abridged by the United States or any state by reason of failure to pay any poll tax or other tax. This was an important legislative step in advancing civil rights, particularly for African American voters in the South, who were disproportionately affected by these taxes as a means to suppress their electoral participation.
Furthermore, the Harper v. Virginia Board of Elections Supreme Court case in 1966 extended the prohibition of the poll tax to state elections, declaring it unconstitutional to require payment of a poll tax in order to vote at any level, thereby strengthening the impact of the Twenty-Fourth Amendment.