By Alan Abramowitz
According to the new Gallup Poll, in the past 10 days, George Bush’s approval rating rose from 40 percent to 45 percent while his disapproval rating fell from 58 percent to 50 percent. That’s a shift from a net approval rating of -18 percent to a net approval rating of -5 percent, a pretty big change. Gallup attributes Bush’s improved poll numbers to favorable public reaction to his response to Hurricane Rita. Perhaps.
But a simpler explanation might be that the new Gallup sample is more Republican and less Democratic than the previous one. Between the Sept. 16-18 Gallup Poll and the Sept. 26-28 Gallup Poll, the proportion of Republican identifiers (including leaners) increased from 38 percent to 43 percent while the proportion of Democratic identifiers decreased from 53 percent to 47 percent. So in just 10 days a net Democratic advantage of 15 points shrank to a net Democratic advantage of just 4 points.
Given the strong relationship between party identification and presidential approval, it is likely that the entire difference between President Bush’s approval rating in these two polls was due to the difference in the partisan composition of the two samples.