Is it possible to vote multiple times in a US presidential election i.e. in more than one state?

Question

It has been reported that the Trump campaign has announced a Nevada lawsuit over non-resident voters alleging inter alia that a significant number of Nevada voters were resident outside the state, and hence under Nevada law ineligible.

If all election law is governed by the state, who is meant to look out for people who may have residences, or voting registrations in multiple states?

In Britain it is possible to be on the electoral roll (a compulsory registration completed annually by householders) in more than one place. However it is illegal to cast more than one vote in the same election e.g. a parliamentary election, held on the same day.

One can in the UK, however, vote in two separate local council elections on the same day - I was surprised to discover - if one is registered in two places.

So is it possible that some of the Nevada absentee voters. also voted elsewhere?

Answer 1

If a voter moves between states, they should be removed from the voter rolls of their previous state. Mechanisms to notify states about residence changes are described here:

HAVA requires states to identify duplicate records on the registration list. States identify duplicates within their borders, and they can also cooperate with other states to identify potential duplicate records across state lines. If a new voter in a state fills out a voter registration form and indicates that he was a registered voter in another state previously, jurisdictions will typically inform the other state that the voter has moved. In recent years there has also been an increased focus on interstate database comparisons that allow participating states to directly compare their data to identify potential duplicate registrations or inaccuracies.

The Electronic Registration Information Center (ERIC) has been joined by well over half of the states. The mission of ERIC is to assist states in improving the accuracy of voter rolls, and also increase access to voter registration for eligible citizens. It provides states with a proactive rather than a reactive method of keeping up with their voter lists, and is a good way to keep up with a mobile population. ERIC also uses resources such as the Social Security death index and NCOA (National Change Of Address) data, which means it can be a “one-stop shop” for many list maintenance and data comparison activities. It provides monthly reports to the states

Answer 2

The process for USA elections requires that the precinct election official has a list of people who are:

1. Eligible to vote.
2. Are registered to vote in this election.
3. Live in the area covered by the polling location.

You are then matched to the list via your government ID, and have to sign something where they can compare your signature to that of the person-of-your-name who voted last time around. This serves as filling your 'slot', and thus nobody else can vote in that precinct under your name. If you go to the wrong polling location, they will be unable to match your name/ID to an eligible voter in that precinct. Using your ID, they can usually direct you to the proper location for you to vote.

If you are unable to vote in your proper precinct (for whatever reason), you can go to the county election board and vote using a provisional ballot. These are subjected to greater scrutiny, and are compared against the list submitted by the precinct at the end of voting such that someone who voted in both locations would have one of their votes thrown out, and submitted for voter fraud.

Now, is there a chance that someone who lived in Nevada and registered to vote there, then moved to a different state and registered to vote there, might have been missed by the Nevada voting commission and thus be left on the list of registered voters so they could vote absentee?

Yes, as we do not yet have a nationwide registry of voters, and while there are safeguards in place to prevent this scenario, county governments have varying degrees of competence in enforcing these safeguards. But as absentee ballots, they are treated to extra scrutiny, similar to the provisional ballot people, and they would be charged with voter fraud when they are caught. So while there is a non-zero chance of one or two people being able to vote twice, thousands of people 'falling through the cracks' is basically unheard-of.