In North Carolina's 2016 primaries, about a third of voters cast ballots early, with the remaining two-thirds turning out on election day.
"If that pattern holds, we could be talking about a million registered voters participating on Tuesday. That would be pretty substantial," said Michael Bitzer, professor of political science at Catawba College, noting that North Carolinians cast just under 800,000 early votes by absentee ballot and at one-stop polling sites this year. There are more than 6.9 million registered voters in the state.
North Carolina has 110 delegates up for grabs in the Democratic presidential primary, which is third most of the fourteen states holding Super Tuesday contests, after California and Texas. A presidential candidate needs a minimum of 15 percent of the vote to qualify for any delegates in North Carolina, which are awarded proportionally to candidates who meet that threshold.
Bitzer said that for the Democratic presidential canididates, winning in North Carolina is not just critical in terms of securing the nomination, but key to building momentum for the general election.
"I think that's what Barack Obama's campaign in 2008 was able to do," Bitzer said. "Build an infrastructure through the primary, keep that infrastructure going through the summer into the fall and made North Carolina, really, the battleground state that we are now."
Republican presidential candidates won North Carolina in 2012 and 2016.
Other key races this Super Tuesday include GOP primaries for state Attorney General and Governor, the Democratic primary for U.S. Senate, and crowded slates of candidates from both parties running for Lieutenant Governor.
Polls open at 6:30 a.m., on Tuesday, and close at 7:30 p.m.