Among pollsters, no consensus on Obama approval rating President Obama has moved up in the latest polls - or is that down? Depends which poll. This week has seen four new public surveys from highly regarded, nonpartisan polling organizations - two one way, two the other. Two other polls show not much change at all. The latest numbers come from the Pew Research Center and show Obama's job approval - probably the most important political statistic at this time of year - at 50%, as against 41% disapproving. That's a big boost - the nine-point favorable margin compares with a four-point margin last month and a four-point deficit in January. The poll, of 1,503 adults, including 1,188 registered voters, was taken Wednesday-Sunday, March 7-11. The survey also showed 59% of voters -- including almost a third of Republican voters -- saying they expected to see Obama win reelection. And it showed a notable improvement in the Democratic party's image among voters, with the public having an overall favorable view - 49%-43%. The public's overall view of the Republican party was strikingly negative, 36%-56%. Half of those surveyed said they would describe the GOP as "extreme" while only 35% said they would use that word to describe the Democrats. Gallup's numbers for roughly the same period track fairly closely with the Pew figures on Obama. The Gallup three-day average for Friday-Sunday had Obama's approval at 49%. As Gallup's Frank Newport noted, that figure puts Obama "on the low end of the range of approval levels at which modern presidents have been re-elected," in other words, in range of victory, but hardly a sure thing. Gallup's historic data has shown that a president's approval ratings in the spring of the election year are a strong predictor of the November results. Gallup and Pew also show similar numbers about the most important factor driving the presidential race - perceptions of the economy. Gallup's Economic Confidence Index over the weekend hit the most positive level (-13) since Gallup started tracking in January 2008, a full year before Obama's presidency began. For the full week, the share of Americans who said economic conditions were "poor," 39%, was at the lowest level since March 2008. In the Pew poll, 44% of the public thought economic conditions would be better in a year, and only 14% thought they would be worse, a level about the same as last month and markedly more optimistic than a few months ago. Two other polls taken over roughly the same period, one by the Washington Post and ABC News and the other by the New York Times and CBS News, showed the opposite trend - Obama's position deteriorating. Pollsters for the organizations attributed the declines to the impact of high gasoline prices and to overall volatility in the race. The New York Times/CBS poll was the most different from the others, showing Obama's approval badly underwater, at 41%-47%. Last month, the same poll showed his approval at 50%-43%. The Post/ABC poll showed a smaller shift. In that survey, Obama's approval was at 46%-50%, as compared with 50%-46% in February. A big driver of the shift in their poll was a spike in disapproval among blue-collar, white voters, a group that has been a persistent weakness for Obama. Among them, only 28% approved of Obama's job performance and 66% disapproved, the Post/ABC poll found. Two other polls released on Tuesday showed relatively little change in Obama's standing, but both had results that were closer to the Pew and Gallup numbers than the New York Times/CBS figures. A Reuters-Ipsos poll put Obama's job approval at 50%-48%, essentially unchanged from the month before. And a Bloomberg News poll had Obama's job approval at 48%, up from 45% in September, when the poll was last conducted. Several factors can account for the differences among the surveys. One big factor is random variation. The New York Times/CBS News poll, conducted March 7-11 among 1,009 adults, including 878 registered voters, has a margin of error of +/-3 percentage points, meaning that the "true" Obama approval rating could be as low as 38% or as high as 44%. The Pew survey's margin of error means its approval rating for Obama could range between 53% and 47%. Even that doesn't fully account for the impact of randomness, since the margin of error only means that 95 times out of 100, the "true" results will fall within the expected range. In other words, out of every 20 polls, one can be expected to be an outlier, showing a result outside the expected margin of error.