A new study of detailed polling supports what I've said here from the beginning: it was Sarah Palin, not that economic meltdown, that sank McCain:
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.
Yeah, "within days of the speech" was when all the information about what an ignorant loon she is came to light. The only question left isn't whether she cost the GOP in 2008, it's whether the GOP will sink itself with her in 2012.