There must be a durable audit trail which forms the legal record of voters’ intents and supports audits which can verify results. The customary, and still quite satisfactory, way of accomplishing this is with a paper ballot that is a record of each voter’s choices. Citizens need to be confident that, if there is any question about the results of an election, there is a guaranteed way to resolve it. An audit or recount will either verify the original result or provide a way to correct it. Audit trails (including all pertinent or related records) should be sealed and saved for at least two or three years after each election.
It is extremely difficult to audit an entire election at one time; it’s hard to manage and there is a high probability of mistakes occurring during the audit. It may be hard to have a high confidence in the audit! This is yet another strong reason favoring voting at polling places with 500 to 2,500 voters assigned to each. Such a small isolated unit can be audited quickly and with very high confidence. The total time and effort to audit all polling places would be less than would be required to audit the entire election as a whole.
Even if election outcomes are not challenged, it is a good standard practice to audit a small number of randomly selected precincts. If significant problems are discovered, the audit would be expanded, perhaps to a total recount. Another similar approach is a risk-limiting audit (RLA). The statistical basis for RLAs is beyond the scope of this course. The concept is to audit a small number of randomly selected ballots to gain an acceptably high confidence that the outcome of a given race is correct. Close races will require a larger ballot sample than races with large margins of victory to achieve the same confidence level. If the ballot sample does not support the result of the race, additional ballots need to be examined which may lead to a complete recount. RLAs are now required in a few states.
Of course, suspicions or accusations of fraud should be decisively resolvable by audits. Audits assure election integrity and their availability builds citizens’ confidence. One of the worst blunders in this regard was the (evidently thoughtless) adoption of the “DRE” (Direct Recording Electronic) voting machine. The DRE had no audit trail. The machine had to be trusted. People don’t trust machines, nor should they, so election integrity took a major hit. The DREs have been phased out as a result of the passage of laws requiring durable audit trails.