How Enthusiasm, Early Voting Can Affect Turnout in Presidential Election

The fear for at least one candidate is that voters stay home on Nov. 8.

— -- The fluctuating enthusiasm surrounding the two leading presidential candidates could have a big impact on voter turnout in this election.

Increasing use of early voting and largely increasing overall turnout in the past several general elections may contribute to a record number of people voting, according to ABC News political analyst Matthew Dowd.

"As a percent of voting age population it will be low, probably lower than the past four or five presidential elections," Dowd said. "Net total will set a record though."

"It could affect down-ballots though, if GOP voters aren't enthused," he said.

The latest ABC News tracking poll released this morning shows that while 56 percent of Clinton's supporters said that they are voting for her because they want to see her in the White House, 54 percent of Trump supporters said that they are voting for him more as a referendum on Clinton than as a reflection of their view on Trump directly.

"When you look at the enthusiasm numbers for each candidate they are below 2012, 2008, and 2004," Dowd said.

In Georgia, voting began on Oct. 17 and there have been at least 432,696 votes cast both in person and by mail-in ballot, according to the secretary of state.

ABC News' John Kruzel contributed to this report.