Early voter turnout data make it only harder to predict North Carolina elections for president, senate and governor.

On Thursday, a day on which early voting sites increased throughout the state, the only clear trend showed that unaffiliated voters have turned out in higher numbers than before, making a hard-to-predict election that much harder.

North Carolina surpassed 1 million early voters on Thursday, and election experts predicted that number to increase in the second week of early voting, as more sites come online. On Thursday, North Carolina had nearly 400 early voting sites open, up from about 250 earlier this week.

Even with fewer locations compared with four years ago, early voting turnout this year has tracked closely in line with turnout from the last presidential election. Some experts predict that early voting turnout will increase compared with four years ago, but caution that doesn’t mean overall turnout will surpass that of four years ago.

Consider this theory: Those motivated to vote this year want to make an extra effort to get to the polls early. Those who have thrown their hands in the air, aren't just waiting for Election Day, they won't show up at all.

Early voting up, Election Day voting down. But how much?

"That’s the great unknown, I would say," according to Michael Bitzer, a Catawba College professor of Political Science who closely tracks election data. "Yes, these folks are showing up in comparable numbers, but the question is, would they have shown up anyway, even on Election Day? Or are they just going ahead and banking their votes and perhaps those folks who aren’t showing up, won’t show up on Election Day, either. So the question is going to be, 'Will we meet the 4.5 million ballots cast in 2012?' I think that’s anybody’s guess right now."

Looking at party affiliation among early voters shows that turnout among both registered Republicans and Democrats was down, while turnout for those registered unaffiliated was up. Registered Democrats have comprised 46 percent of the early voters, while Republicans make up almost 30 percent of turnout. Unaffiliated voters count for nearly one-quarter of total early turnout.

"That’s not surprising to me, when I thought about it, because the fastest growing group of registered voters are registering unaffiliated," said Bitzer. "And the question in my mind, is, are these registered unaffiliateds true independents, or do they simply abhor the label, but they vote for the party that they lean to one way or the other?"

By using data from the last presidential election, a growing base of unaffiliated voters could portend good things for the Republican Party. Exit poll data from four years ago showed that unaffiliated voters in North Carolina chose Mitt Romney over Barack Obama by as many as 15 percentage points, which essentially propelled Romney to carry the state.

Joe Cabosky, an assistant professor in the UNC-Chapel Hill School of Media and Journalism who studies voter data, says Donald Trump, Pat McCrory, or Richard Burr would not need to carry unaffiliated voters by the same margin as Romney to win, but predicts that whatever candidate wins that block of voters will win the election in their respective statewide race.

Another data point favorable to Republican candidates is that more unaffiliated voters participated in the Republican primary this year than in the Democratic primary. In North Carolina, a voter registered as unaffiliated may participate in either – though not both – primary election. This year, 56 percent of unaffiliated voters cast a ballot in the March primary. Of those, 54 percent participated in the Republican primary, while 46 percent participated in the Democratic primary.

Of course, measuring primary participation is not necessarily a predictor of general election outcomes. Many North Carolina counties are so polarized that many contests for down-ballot races like county commissioner or statehouse representative are effectively decided at the primary. Even if a resident of that county typically associates with the opposing party, she might choose the opposing primary simply to have a say in the de facto election for a down ballot candidate.

"We have become so polarized in the counties ... that some voters are indeed registering unaffiliated," said Bitzer. "They may not necessarily approve of a particular party that they’re voting in but they want to do something to have a voice, (and) the primary elections that have become more and more the deciding election, particularly at the local level."

In an election that has frustrated even the most seasoned pollsters, a rise in unaffiliated voters is only further fogging the crystal ball.

"There are a lot of X factors that are shifting in ways we haven’t seen before," concluded Cabosky. "I think there is good and bad news for both parties. ... I honestly don’t think it offers much clarity."