The president's approval rating is dipping into dangerous territory, but that doesn't tell the full story

For President Obama, the news just never seems to get any better.

As unemployment continues to remain high and the economy fails to reignite, his approval rating has steadily declined , reaching new lows in the past week. If history is any guide, those numbers seem to indicate that Obama's road to re-election may be impossibly steep. But there are some reasons why it's not quite hopeless yet.

The latest Gallup tracking poll, conducted from August 25 to the August 27, shows that 38 percent of Americans approve of the president's performance, while a staggering 55 percent disapprove. Of the presidents who have won re-election since Harry Truman, none had performance ratings that low during the 14 months before the election. A poll from the Associated Press and the publicity firm GfK, taken August 18-22, also showed that frustration with the White House is growing, with 52 percent of Americans disapproving of Obama's performance. The AP poll shows 46 percent of Americans approving, much higher than Gallup's figure but still the lowest yet in the AP's polling.

Political analysts look at job performance ratings because they tend to be the best overall estimate of an incumbent candidate's prospects. People are either happy with the job he's doing, or they aren't. "It's a summary statistic," says Larry Sabato, a professor of political science at the University of Virginia. "The prognosis for Barack Obama would be grim indeed if the election were held in November of 2011," Sabato says. But it's not the only measurement. Polls also show that, when asked whether they'd vote for Obama or an unnamed Republican, more people pick Obama - and Obama polls fairly well against the current Republican nominees. "He can be very vulnerable, but if people find the opposition less acceptable, it may not matter," says Jennifer Duffy, senior editor of the Cook Political Report. The AP poll also showed that 47 percent of Americans think Obama deserves re-election, while 48 percent believes he deserves to be voted out -- a statistical tie, which seems to show that even though voters are frustrated with the president, they haven't quite given up on him, either.

Yet another glimmer of hope for Obama is time.

As the campaign season nears, perceptions will change. Die-hard partisans who've been disillusioned with the president will likely begin to fall back into his column. The economy won't be able to turn itself around completely by then, but any positive movement may be able to convince Americans that things are on a better track. Sabato noted that, in terms of predictive value, approval ratings only become really relevant the summer before the election, giving Obama about a year to turn around his public perception.

Most analysts believe Obama's fortunes will rise or fall with the economy. But even though the unemployment rate likely won't be much lower on election day than it is today, that doesn't mean it is hopeless for Obama. More important than the rate itself is the economy's movement -- if there are visible signs that it's improving, voters may decide that things are moving in the right direction, even if the overall picture remains dismal.

Still, Obama's re-election chances are looking less stable by the minute.

That's why the next few months -- perhaps the last chance for the White House and Congress to pass a jobs measure that sticks -- will be crucial to Obama's political future.