PRINCETON, NJ -- Most Americans believe President Obama will win the presidential election this fall, even though the race has been highly competitive for most of the year. Americans' expectation that Obama will win has been remarkably consistent, virtually unchanged since May despite three intervening months of campaigning.

The results are based on an Aug. 20-22 USA Today/Gallup poll.

Americans' prediction of who will win is significant since they have generally been correct in predicting the winner of past presidential elections.

Of course, Americans' beliefs about who will win are influenced by their preferences. Those who say they would vote for Obama if the election were held today overwhelmingly believe he will win, by an 86% to 9% margin. One reason Obama has the edge in overall predictions about the election is that Romney voters are less positive that their candidate will prevail, with 28% saying Obama will win, compared with 65% who believe Romney will win.

Election predictions also show expected party differences, although Democrats are more optimistic about their candidate's chances (80% say Obama will win) than is the case among Republicans (60% say Romney will win).

By 58% to 35%, independents say Obama will win. This is the case even though independents' vote preferences have been closely divided this year.

Most Believe Quality of President Depends on Outcome

Americans clearly think the outcome of the election has consequences for the quality of the next president, as nearly seven in 10 think only one of the two candidates would make a good president. That includes 38% who say only Obama would be a good president and 31% who say only Romney would be. Twelve percent believe both men would make good presidents, while a slightly higher percentage, 17%, believe neither would.

In 2008, 25% thought both Obama and John McCain would make good presidents, roughly twice as many as say so about Obama and Romney now. The current figure is more in line with the 15% Gallup measured in September 2004 for that year's contest between George W. Bush and John Kerry.

As expected, Democrats and Republicans overwhelmingly think only their party's candidate would be a good president. More independents say only Obama would be a good president than say only Romney would. However, independents are also more likely to say neither would be a good president than to say both would be.

Obama supporters are significantly more likely to believe he would be a good president -- 90% say so, including 75% who say only he would and 15% who say both he and Romney would be -- than Romney supporters are to believe Romney would be a good president (76%).

Implications

Although the presidential race between Obama and Romney has generally been a tight one, Americans by a fairly wide margin expect Obama to win. That could be because he is the incumbent, and incumbents are generally more successful than not at winning a second term in office.

The implications of this "expectation" measure on voter behavior and the election outcome are not clear. At this point, a significantly higher percentage of Republicans say they will vote for Romney than believe he will be able to beat Obama in November. These partisan views on the part of Republicans that their candidate is the underdog could motivate them to campaign for their candidate and get out and vote, or could be discouraging and end up suppressing their vote. Similarly, Democrats' confidence that their candidate will win could encourage them to get out and vote to make sure that is a reality, or could cause complacency and lower their turnout percentage.

During the last three months, Romney's campaign efforts have done little to persuade Americans that he is likely to win the presidency. He will have a prime opportunity this week at the Republican National Convention to make his case to voters as to why he should be elected, that he would make a good president, and to convince them that he is a viable contender for the presidency.

Sign up to get Election 2012 news stories from Gallup as soon as they are published.