PRINCETON, NJ -- President Obama's job approval rating dropped to 40% during the week spanning Aug. 8-14, the lowest weekly average of his administration. During this period, Obama's three-day rolling average also hit a new low of 39% for Aug. 11-13, the first such average below 40% since he took office, though it recovered to 41% for Aug. 12-14.

Obama's weekly average was 42% for the two weeks prior to last week, which at that time also marked new lows for his administration. His lowest three-day average prior to Aug. 11-13 had been 40%.

With the exception of a dramatic national or international event, it is usually difficult to pinpoint the causes for the short-term ups and downs in a president's job ratings. In the current situation, it is reasonable to assume that several events of the last few weeks have played a part in depressing the public's approval of Obama. These include the widespread public disapproval of the way Washington handled the debt crisis, a substantial drop in the public's confidence in the economy, and last week's gyrations in the stock market.

Additionally, there was substantial news coverage of the Republican presidential candidate debate and the Ames Straw Poll in Iowa at the end of last week, including harsh criticism of Obama from all of the Republican contenders.

Implications

Although the new lows in Obama's job approval rating represent only a slight drop from his previous low readings, they symbolically underscore the weaker position the president is in as he begins a "listening tour" of the Midwest this week.

Ten incumbent presidents have sought re-election since World War II, and none has won a second term with final pre-election job approval ratings below 48%. The last two presidents who lost their re-election bids -- George H.W. Bush and Jimmy Carter -- had job approval ratings in the 30% range in the fall of the election year. Thus, Obama's challenge is not only to move his rating back above 40%, but also to push it close to or above 50%.

The crucial period for Obama will begin after Labor Day, given the relative quiet on the political front that should be the case before then. Obama will generate some news coverage this week with his bus tour through Minnesota, Iowa, and Illinois, but after that, he has a scheduled vacation on Martha's Vineyard, during which he will be largely out of the news -- barring some major crisis. Republican candidates will continue campaigning over the next several weeks, but with no major debates or other events scheduled until September, they too will not be generating as much news as they have during the past week.

September will bring more GOP debates and an increasing focus on the budget situation, as the new congressional "supercommittee" begins its work and as Congress and Obama return to Washington. If the president is not able to turn around the negative momentum in his ratings during the fall months, it may be more and more difficult for him to do so as the presidential campaign begins in earnest next year.

Explore President Obama's approval ratings in depth and compare them with those of past presidents in the Gallup Presidential Job Approval Center.