Low income citizens cannot afford to pay the poll taxes. If they don't pay poll taxes, they can't vote. Incidentally, poll taxes have been outlawed in the United States.
Yes, that is part of the voting rights act.
The Twenty-fourth Amendment (Amendment XXIV) prohibits both Congress and the states from conditioning the right to vote in federal elections on payment of a poll tax or other types of tax.
the Poll tax
Poll taxes affected African Americans in the southern United States during the Jim Crow era. The taxes were used as a way to disenfranchise African American voters by making it difficult for them to pay the required fees in order to vote. This discriminatory practice was eventually outlawed by the Voting Rights Act of 1965.
The 24th amendment prohibited poll taxes
24th Amendment
by eliminating poll taxes
The Poll Tax prevented people who did not have the money to spare to vote. It was a technique used to restrict voting.
Poll taxes and Literacy laws were two of the primary ways that some states kept minorities from voting. Poll taxes were set to a point that would not be difficult for White people to afford, but Very difficult for Minorities. White voters would be given something simple to read, and minorities would be given bits of Shakespeare. Many states removed them voluntarily as they saw the way the mood of the country was moving, and as State Legislatures became more enlightened. However, for those states that did not, the Civil Rights Act of 1964 ended the practices everywhere for good. The Twenty Fourth Amendment, ratified in 1964, outlawed poll taxes. The Voting Rights Act of 1965 was the law that outlawed literacy tests.
Poll Taxes
After the Civil War, some southern states created poll taxes — or fees charged in order to vote — as a way to bypass the Fifteenth Amendment. Since many African American citizens could not afford to pay the tax, they were unable to vote. The Twenty-Fourth Amendment outlawed poll taxes in federal elections.