Hey, I caught a pattern in Oct. 2008

Via Dave Weigel, I came across this political science data relayed by Richard Johnston and Emily Thorson regarding Sarah Palin's apparent effect on John McCain's campaign:

John McCain’s August 29 announcement of Palin as his running mate surprised the Republican establishment, the media, and especially voters. She made a strong first impression: she enjoyed high approval ratings after her acceptance speech, and the percentage of voters saying that they intended to vote Republican skyrocketed. But within days of the speech, her ratings began a precipitous slide from which she—and the McCain campaign—never recovered. Throughout the rest of the campaign, vote intentions were closely tied to Palin’s approval ratings: each major Palin approval drop was followed, within a day or two, by a drop in McCain vote intention. No other factor moved McCain support with such precision. Comparison of the correlation between running mate approval ratings and vote intentions from 2000 and 2004 confirms Palin’s peculiar importance in 2008.

 I hold that truth to have been self-evident -- per xpostfactoid, Oct. 24, 2008:

Palin sinks under Obama's light touch

The polling evidence is overwhelming that Sarah Palin is dragging McCain down. And the reason is simple. While Democratic news junkies may be convinced that she's a Putinesque thug (see the Troopergate report), a quasi-fascist demagogue (whipping up mobs to violent fantasy) and a Christianist kook (accepting a laying on of hands from an avowed anti-semite to protect her from witchcraft), most Americans view her simply as likeable but unqualified. According to the latest Washington Post-ABC News poll:

The shift in Palin's ratings come with a pronounced spike in the percentage of voters who see her as lacking the experience it takes to be a good president. Voters were about evenly divided on that question a month and a half ago, but toward the end of September a clear majority said she was not qualified. In the new poll, 58 percent said she is insufficiently experienced. read more

Speculating that "McCain's age and medical history" may have highlighted the importance of Palin's inexperience, Johnston and Thorson also concede, like good scientists, "One could as easily say that she gave him a significant but unsustainable boost and that the rest of the campaign consisted mainly of shifting focus away from this distraction."  But the polling data cited in my '08 post show indicate pretty clearly thatthey are right with their primary hypothesis -- e.g., a Newsweek poll finding that "Nearly a third of voters, 31 percent, say that McCain's choice of Palin makes them less likely to vote for him, while 19 percent say the Palin pick makes them more likely to choose McCain."

Go big and bold, Romney!