151. Voter turnout quorums (minimum numbers of voters casting ballots) are required in several cases, including presidential elections, mayoral elections (only at the first round) and state referenda. When the necessary threshold is not reached, an election must be repeated, yet the repeat election(s) may be no more successful. Thus, there is a possibility for a cycle of failed elections (with the exception of the mayoral elections) and, in addition, an incentive for fraudulent practices to inflate the recorded vote.
