Guest Pollster | October 8, 2009
Topics: Barack Obama , Charts , job approval , Michael McDonald , Pollster.com
This guest contribution comes from Michael McDonald, an Associate Professor of Government and Politics in the Department of Public and International Affairs at George Mason University and a Non-Resident Senior Fellow at the Brookings Institution.
Saturday Night Live's sketch mocking Obama prompted CNN to run a story stating that the 'SNL' Obama sketch marks end of [Obama's] honeymoon. Actually, SNL is not leading public opinion here. Polling suggests that Obama's honeymoon ended in early August. Since then, Obama's job approval rating has remained essentially flat.
If you are an Obama supporter, you might ask how this is possible, since an Oct. 1-5 AP-GfK survey shows a resurging six percentage point increase in support for Obama since their Sept. 3-8 survey. Or, if you oppose Obama, you might point to the slight downward trend in Obama's job approval among all polling firms from early September clearly evident on Pollster.com.
What is going on here is that Pollster.com's trend line behaves fine when there are lots of polls to average together, but it does not work as well when two daily tracking polls are averaged together with more sporatic national polling. The two daily tracking polls - Gallup and Rasmussen - consistently find lower Obama job approval ratings than other polling firms. In addition to these two daily tracking polls, there are approximately bi-monthly internet polls from YouGov/Polimetrix and Zogby that also consistently show lower Obama job approval numbers compared to other polls.
These so-called "house effects" whereby different pollsters consistently report different numbers is well-known. I do not want to get sidetracked into speculation about why these polls have lower numbers, since we really cannot know what the true population value is for Obama's job approval rating.
What is interesting is what happens when these polls are disaggregated into two types (1) the tracking and internet polls and (2) all other polls.
To examine the first type of polls, let's use Pollster.com's filter tool to include all internet polls and the two daily tracking polls.
According to this trend estimate, Obama's job approval rating leveled out in early August at about 50 percent, and may be slightly increasing since.
To examine the second type of polls, let's use Pollster.com's filter tool to exclude all internet polls and the two daily tracking polls.
According to this trend estimate, Obama's job approval rating leveled out in early August at about 53 percent.
Seen in this light, Obama's job approval rating has remained steady since early August, and it is here that Obama's honeymoon likely came to an end. Most pollsters took a vacation during August, except those conducting the first type of polls, which show lower Obama job approval than the second type. The bump up in Obama's job approval at the beginning of September is an artifact of the increased number of the second type of polls conducted when Obama delivered his health care speech to Congress. Subsequently, the absence of the second type of polls allows the first type of polls to again dominate the trend line, thereby giving the appearence that Obama's approval is now decreasing from the (non-existent) short-term early-September rally. The different mixes of the first and second types of polls are confounding the trend line and incorrectly coloring perceptions of the direction of Obama's job approval rating. Indeed, if you squint closely at Pollster.com's trend line for all pollsters, you'll see a long-term periodicty that apparently fluctuates along with the mix of the first and second types of polls.
[Editor's Note: So that Professor McDonald's commentary will always match the graphics, we replaced the embedded, interactive version of charts with screenshots, although you can click the link above each chart to see the most recently updated version with the filtered polls he selected].