Very interesting data from NHPR:
In the 2016 general election, according to the Secretary of State’s office, Election Day registrants of all kinds made up about 11 percent of all ballots cast. Within that, first-time New Hampshire voters made up 6 percent of all votes in November — and, within that, first-time voters who registered without a New Hampshire driver’s license made up less than one percent.
When people talk about the potential for “voter fraud” in New Hampshire, they often point to the idea that the state allows people to register on Election Day and to use out-of-state licenses. But that alone doesn’t mean those voters are doing anything illegal.
There are reasons why someone might legitimately register to vote with an out-of-state license – most obviously, they could have moved to the state recently or could be attending college here. (The state makes clear that out-of-state students attending college in New Hampshire are allowed to vote here, as long as they aren’t also voting in another state.)
To register with an out-of-state license, you still have to prove that you hold domicile in the state – using a utility bill or lease, for example, or by signing an affidavit affirming you actually live where you’re trying to vote. See here for more details on what’s required for first-time voters to register in New Hampshire.
According to the data provided by the Secretary of State’s office, 5,903 people newly registered to vote in New Hampshire using an out-of-state license on the day of the last election.