We estimate 3% of the U.S. voter population is registered to vote in two states. Which state these double-registrants choose to vote in reflects incentives and costs, being more prevalent in swing states (higher incentive) and states which automatically send out mail-in ballots (lower cost). We call this behavior cross-state strategic voting (CSSV) and estimate there were 317,000 such votes in the 2020 presidential election.
No doubt, in most cases double registrations are innocent. I assume the most common scenario is that a person moves, and doesn’t bother to terminate his registration in the state from which he departs. But, if this study is correct, there are a great many voters who know they are registered in two states, and make a conscious decision which state to vote in, generally choosing the state with the closer election or where voting is easiest. By these authors’ calculations, around 317,000 votes were thus cast “strategically” in the 2020 presidential election.
There are two separate issues here. The first is strategic voting, where the voter decides which of two states to vote in. The second is the possibility that the voter may cast two ballots.
The authors conclude that around one percent of double registrants voted twice in 2020. They consider that number reassuring, but it represents around 60,000 illegal ballots.
The authors assure us that that since both Democrats and Republicans vote strategically, the net impact of 6,100,000 dual registrations is small. But they also acknowledge that “Democrats outnumber Republicans 2:1 among double registrants.”
Double registrations are one of many ways in which fraud can influence election results, and one of many reasons why so many Americans lack confidence in the integrity of our elections.