DURHAM, N.H. >> Voter turnout is always important in New Hampshire's presidential primary, but a new study concludes population turnover also will play a big role.

A report by the Carsey School of Public Policy at the University of New Hampshire estimates that more than 30 percent of potential voters were either not old enough to vote in 2008 or have moved to the state since then. A similar analysis comparing the 2000 and 2008 electorates found a similarly high turnover — 33 percent of those eligible to vote in the 2008 primary had not been part of the 2000 electorate.

Contrary to the image of deeply-rooted Yankees, New Hampshire has one of the nation's most mobile populations. Only a third of those ages 25 and older were born in the state. A second demographic force influencing the electorate is aging: Between 2008 and 2015, 129,000 residents turned 18. Together, those turning 18 and those moving into the state represent 326,000 potential new voters, or about 30 percent of those eligible to vote this year.

"Young voters and people who have moved into the state in recent years are two powerful demographic forces that are reshaping the New Hampshire electorate," said co-author Kenneth Johnson. "So judging what's going to happen in the New Hampshire primary based on what's happened in the past is perilous."


The report explores the impact of those changes by dividing potential voters into three groups — established voters who resided in the state in both 2008 and 2016, migrant voters who have moved to the state since 2008 and young voters who turned 18 after 2008. It concludes that the changes have resulted in significant growth in the Democratic primary base.

Young voters are slightly more likely to consider themselves Democrats compared to migrants or established voters, and they are significantly more likely to have a liberal ideology. Nearly 35 percent of young voters classify themselves as liberal, compared to 26 percent of migrants and 232 percent of established voters.

The report also assesses how population turnover has changed the state's political geography. Voter participation in recent Democratic primaries has nearly doubled, creating a Democratic primary base that is larger and more geographically widespread. On the Republican side, participation grew only slightly from 2000 to 2012, and increasing numbers of GOP primary voters now come from the state's two most populous counties in the southern part of the state.