Two new polls released this week show President Barack Obama's approval rating sinking since last month, and one finds Obama at a new all-time low. But other polls conducted around the same time fail to show an Obama plunge, suggesting that at least some of the dip could be statistical noise.
The CBS News/New York Times poll released Monday found Obama's approval rating at a new low for that poll, at 41 percent approval and 47 percent disapproval. Obama's previous low in CBS polling was 43 percent, in both September and November 2011. Along with being a new low in CBS polling, the result was also a 9 percentage point drop from February, when a CBS/New York Times poll found Obama's approval rating at 50 percent.
Another poll released Monday, by ABC News and the Washington Post, found Obama's approval rating falling to 46 percent, from 50 percent since February. Together, the two polls have invited questions about the effects of rising gas prices on Obama's rating.
However, other recent polls show his approval rating rising or staying steady over the past month, signaling that any drop in approval by the latest polls could be random statistical variation.
Obama's approval rating per Gallup shows no change and slight improvement. The tracking poll, conducted March 10-12, finds Obama's approval rating at 47 percent, about the same as Gallup found a month ago and up slightly since a week ago.
Rasmussen Reports' daily tracking over the same period finds Obama's approval rating at 49 percent, although its polling also showed a 51-percent disapproval rating.
A Daily Kos/SEIU survey released Tuesday and conducted by Democratic pollster Public Policy Polling, finds Obama's approval at 48 percent and disapproval at 49 percent. Its previous poll, released a week ago, found Obama's approval slightly lower, at 46 percent. One month ago, the survey also showed Obama's approval at 46 percent.
Most other available data, including the Huffpost Pollster trend estimate, which takes into account all available public polling on the measure, found Obama's approval rating around its lowest last August through October and has shown it mostly on the upturn since then. The estimate shows Obama's approval rating about even, at 47.5 percent approval and 47.7 percent disapproval.
But while there might not be enough evidence to support the idea that Obama's approval is at an all-time low, it still could be dipping. By customizing the Huffpost Pollster chart to be more sensitive to the most recent polls, the trend shows signs of a slight downturn in Obama's approval since February, when most pollsters showed his approval ratings at a particularly high point.
The less sensitive poll estimator can at times "spot" a new trend before the more moderate estimator, but it is also more likely to chase outliers in the data. As reporter Nate Silver points out, it can be difficult in situations where very little poll data is available to discern whether a given result, or even two, is a result of real changes or random statistical variation.
The available evidence from the broader spectrum of available polls does not so far support the idea of a dramatic drop in Obama's approval, but does suggest that in the last month his rating has either leveled off or turned down slightly.
The CBS/New York Times poll was conducted March 7-11 among 1,009 adults, and has a margin of error of three percentage points. The ABC News/Washington Post poll was conducted March 7-10 among 1,003 adults and has a margin of error of plus or minus four percentage points.