What checks and balances exist to prevent fraudulent voting?

Answer 1

Checks and balances from a Federal election basis exist in the fact that each State manages its own voting procedures and rules. Most states have a State Board of Elections established to manage the voting process. Therefore checks and balances will be unique to the state. Election Officials, Monitors, and Poll Watchers exist in most states. One of their roles is to prevent fraudulent voting.

One check and balance that exists in every state is the right for a citizen or candidate to file a complaint and eventually a lawsuit. Therefore the court system is the final check and balance against fraudulent voting.

Answer 2

Using statistics such as exit polls that do not match with final results is one of the ways states prevent fraudulent voting. Additionally, verifying the accuracy of voting machines and certifying them is another way states prevent electoral fraud.