[Gallup, Politico/Morning Consult, Approval chart, Gallup historical data].
The difference for Rasmussen is painfully obvious when you look at our job approval chart, magnified by the sheer number of data points they contribute to the chart.
I know that Charles Franklin is working on a post that will discuss the impact of the Rasmussen numbers of the job approval chart, so I am going to defer to him on that aspect of this discussion.
Due in large part to the Gallup Daily tracking poll, which debuted in 2008, the Obama approval chart is based on twice as much data as the Bush chart 2,886 individual polls as of this writing.
We set their values based on a job approval chart Pollster.com created for President George W. Bush in late 2007, based on just over 1,400 poll results during his presidency.
What the polling average says - HuffPollster's Obama approval chart shows Obama's approval so far remaining steady at just below 43percentt, even with the chart set to "less smoothing" to allow for the possibility of a sudden change.
These results put Obama's current job approval rating at 49.4percentt when plotted on the HuffPost Pollster Obama job approval chart, which combines results from all national polls (and is set to show "less smoothing" to more accurately capture the September increase).
We did this with the Obama job approval chart back in March for similar reasons -- "As a result [of the large number of polls], our default trend lines were smoothing out too much variation, missing some real but short-lived changes".
As you go farther up the approval-ratings chart, you begin to see exceptions to the rule: George H. W. Bush's approval ratings were still high in late 1991, but he lost.
After obtaining Institutional Review Board approval, a retrospective chart review of all subjects with scleral buckle infection was performed.
