ATLANTA - Never have American voters reelected a president whose work they disapprove of as much as Barack Obama's. Not that Mitt Romney can take much comfort - they've never elected a challenger they view so negatively, either.

Unless things change dramatically, this Election Day will mark a first, no matter who wins. The victor will be a sitting president with a slow economy, 8 percent-plus unemployment, and an average Gallup job-approval rating below 50 percent. Or he'll be a challenger who isn't liked personally by a majority of the public and faces notable discord within his own party.

Polls since the nominating conventions show Obama slowly widening a slight lead nationally and in several key states that could decide a close election. And the mere fact that Romney hasn't ever notched a clear lead in polling, unlike previous winning challengers by this point, underscores his struggle to strike a chord with an electorate that isn't exactly enamored with the incumbent.

The presidency already gives certain campaign advantages to the Oval Office occupant, and history indicates that the longer Romney looks up at Obama, the greater the president's chances at a second term.

History, of course, isn't predictive. But it does provide context to help understand the current state of the race.

Some Republicans point to 1980 as hope for a Romney rebound. That year, Ronald Reagan pulled away from President Jimmy Carter in late October to win in a landslide that has reached almost mythical status in GOP annals. But there are many reasons why this is not 1980, not the least of which are that Romney is not Reagan and Obama is not Carter.

From Labor Day through late October, Carter was tied with or led Reagan. But, unlike Romney, Reagan had led for most of the summer, and Carter hadn't polled better than 41 percent since the spring, well below Obama's lowest head-to-head numbers this year.

Many Republicans, meanwhile, are growing restless following Romney's lackluster convention, his comments on Middle East unrest and the release of a secretly recorded video that showed the GOP nominee dismissing 47 percent of the country as believing they are "victims" and dependent on handouts.

'Our election to lose'

Still, says Republican Sen. Lindsey Graham of South Carolina, "This is our election to lose. If Obama wins, he'll be rewriting political history."

Using historical Gallup job approval ratings in election years - in September where possible - Obama ranks below the seven presidents who have been reelected since 1948. But he is in a stronger position than the three - Carter, Gerald Ford, and George H.W. Bush - who lost. The three losing presidents all had unemployment rates lower than today's, but the overall economic circumstances vary.

Obama's personal favorability ratings have consistently been higher than his job approval ratings. Republican strategist Timmy Teepell, who manages gubernatorial, House and Senate campaigns for the GOP, credits independents with the difference. "They may not like what he's done," he said, "but they think he's a good guy and he's trying hard."

A tough primary race

Voters with negative impressions of Romney, meanwhile, have outnumbered those with favorable impressions for much of his bid. That dynamic was fueled in no small part by a crowded primary field that hammered Romney on everything from his moderate record as Massachusetts governor to his business ventures at Bain Capital.

At Romney headquarters, the official line is optimism. Top pollster Neil Newhouse proffers the Politics 101 method for beating an incumbent. At the same time, he acknowledges that Romney's effort so far isn't enough.

"We recognize that over the next seven weeks we need to not just make the case why Barack Obama doesn't deserve a second term," Newhouse said, "but also to paint a picture of how a Mitt Romney presidency would be different and better."

With Romney working on the second part of that effort, the president has capsized the usual rules of an incumbent election and, in some respects, made Nov. 6 a referendum on Romney in addition to one on Obama's first term.

"We've just done a better job telling the president's story than they've done telling theirs," says Paul Begala, a veteran Democratic strategist who is advising the pro-Obama Super PAC Priorities USA Action.