How did the "Secret Ballot" effect political machines?

Secret ballots are used in conjunction with various voting systems. The most basic form of a secret ballot utilizes blank pieces of paper upon which each voter writes his or her choice. Without revealing the votes to anyone, the voter folds the ballot paper in half and place it in a sealed box. This box is later emptied for counting. An aspect of secret voting is the provision of a voting booth to enable the voter to write on the ballot paper without others being able to see what is being written. Today, printed ballot papers are usually provided, with the names of the candidates or questions and respective check boxes. Provisions are made at the polling place for the voters to record their preferences in secret, and the ballots are designed to eliminate bias and to prevent anyone from linking voter to ballot.