Bush's numbers and statistical nearsightedness

First, take a close look at this picture:


Then, tell me that it makes sense -- in the wake of al-Zarqawi's death and Bush's surprise 5-hr visit to Baghdad -- to pay any attention to:

• A one-point rise (NBC/Wall Street Journal over a 6-week time span)
• A two-point drop (CBS over a 3-week span)
• Or a two-point rise (USA Today/Gallup over a 1-week span)

(Note, these are the only post-Zarqawi numbers.) When his approval jumps 10 points in as many days, as it did when Saddam Hussein was captured in December 2003, then we'll talk. Otherwise, we've gotta take the long-view. The short-term ups and downs of single polls by single polling firms mean next to nothing. So, Democrats and Republicans alike: stop yer yakkin'. A "bump" exists if all the polls agree, the bump is large, and it's sustained.

Joe in DC at AmericaBlog has comments, as does Tim Grieve at Salon.com.

See PollingReport.com for the numbers.