Nick Szabo extolls the not-so-obvious benefits of unpredictable elections:
If would-be purchasers of political favors cannot predict who will win, or even who might win with substantial probability, they cannot purchase any favors prior to an election. A perfectly unpredictable election would be bribe-free.We can’t make elections perfectly unpredictable, but we can get pretty close. There are historical and even contemporary precedents. For example, we choose jurors by lot from a pool much larger than the twelve jurors selected. This prevents wealthy plaintiffs, defendants, or governments from buying jurors through the selection process. (After selection, there are a number of legal and physical sequestering mechanisms that can be used to isolate a jury from contact with favor purchasers. As for political office, this article deals only with bribery during the selection process).
In ancient Athens, not only juries but many office-holders were selected by lot. But the most intriguing unpredictable election process was probably that of the medieval Venetian Republic. This republic helped turn a secure island into Europe’s wealthiest trading empire. In Venice, many political offices were selected by a repeated cycle of lottery, vote, … lottery, vote. The final lottery and vote, at least, were held one after the other in the same room, giving favor purchasers no time or privacy to do their business. The leading office in Venice, the Doge, was selected by a Great Council of about 2,000 members from those members, through a process [of lotteries and votes].
The process is loosely similar to the confusion/defusion cycles of encryption or the repeated mixing phases used for securely anonymous Internet communications. The Venetians alternated a randomizing step with a debate-and-voting step.