An ID card to vote would be a poll tax if it was at all costly or difficult for some to acquire.
Am I going to get a "knock on the door" asking me to explain how Fidel's proletarian paradise knew so much about the poll tax?
A tax required as a qualification for voting. After the Fifteenth Amendment to the Constitution extended the vote to blacks in 1870, many southern states instituted poll taxes to prevent blacks from voting. The Twenty-fourth Amendment to the Constitution, adopted in 1964, prohibits poll taxes for federal elections.