Republican and Democratic campaigns in New Hampshire have been trying to woo the crucial voting bloc of independent voters, who can vote in either primary. The NBC News Exit Poll finds similar participation rates by independent voters in both party primaries today as in past years.
Early exit poll results show that 42 percent of Republican primary voters in this year's race consider themselves to be political independents, and a similar 40 percent of voters in the Democratic primary think of themselves as independents.
In 2008, the last time both parties had an open nomination contest, slightly more voters in the Democratic primary (44 percent) identified themselves as independents than did voters in the Republican primary (37 percent).
In 2000, the share of independents in each primary was fairly comparable, just like this year — 40 percent in the Democratic primary and 41 percent in the Republican race.
In both 2000 and 2008, John McCain rode strong performances among independents to win the GOP primary, overcoming the slight partisan edge George W. Bush and Mitt Romney had with self-identified Republicans in those respective contests.
On the Democratic side, though, Barack Obama's 10-percentage-point lead among independents in 2008 and Bill Bradley's 12-point advantage in 2000 were not enough to overcome the strong partisan support enjoyed by the eventual New Hampshire winners — Hillary Clinton in 2008 and Al Gore in 2000.
The role these New Hampshire's independents play in 2016 will become clearer as the voting results come in tonight.
This story first appeared on NBCNews.com.