The presidential debates: They're the next big thing in the race for the White House.

So which candidate will have the upper hand in next month's showdowns?

Most voters think President Barack Obama will have an advantage in the three debates, according to a new national survey. And a CNN/ORC International poll released Tuesday also indicates Obama's approval rating at 51%, a gray area for an incumbent president running for re-election.

Fifty-nine percent of likely voters questioned in the survey say that Obama is more likely to do a better job than Republican presidential nominee Mitt Romney in the debates, with 34% saying that Romney will beat Obama.

"Then Sen. Obama had the same edge over Sen. John McCain when voters were asked four years ago who would win the 2008 debates," says CNN Polling Director Keating Holland. "Going back even further in the history books, Ronald Reagan, Bill Clinton, and Al Gore were all seen as more likely to win their debates."

While only five percent of Democrats think that Romney will have the upper hand in the October showdowns, 18% of Republicans say that Obama will have the advantage.

The debates are scheduled to be held on October 3 in Denver, Colorado, October 16, in Hempstead, New York, and October 22 in Boca Raton, Florida. CNN Chief Political Correspondent Candy Crowley, anchor of "State of the Union," will moderate the October 16 debate. Vice President Joe Biden and Rep. Paul Ryan, the GOP vice presidential nominee, face off on October 11 in Danville, Kentucky.

The CNN poll was conducted Friday through Sunday, entirely after last week's Democratic convention in Charlotte, North Carolina. According to the survey, 51% of adults nationwide approve of the job Obama is doing in the White House, with 44% saying they disapprove. The 51% approval is up three points from last week's CNN poll, which was conducted before the Democratic convention.

By a 55%-39% margin, women approve of the job Obama's doing, with men divided (48%-49%).

So how does Obama's approval rating two months before the election compare to the most recent presidents running for a second term in the White House?

Incumbents with an approval rating under 40%, such as Jimmy Carter in 1980 and the elder George Bush in 1992, lost their re-election bids. Incumbents with an approval rating hovering around the 60% mark, such as Ronald Reagan in 1984 and Bill Clinton in 1996, won re-election. Only one incumbent in recent history, George W. Bush in 2004 at 52%, has been in that territory in the middle. Bush narrowly won re-election.

"Remember that a president's approval rating is not necessarily a good indicator of his ultimate share of the vote. For one thing, the approval rating is based on the views of all Americans, but all Americans do not vote," adds Holland. "Also bear in mind that the group of Americans who disapprove of Obama include some liberals who have a negative view of him because he has not been liberal enough. That group may ultimately conclude that Obama is the lesser of two evils and reluctantly vote for him."

The CNN poll was conducted by ORC International, from Sept. 7-9, with 1,022 adults nationwide, including 875 registered voters and 709 likely voters, questioned by telephone. The survey's overall sampling error is plus or minus three percentage points, with a sampling error of plus or minus 3.5 percentage points for likely voters.