If the Palin pick has done nothing else, it’s got Obama supporters second-guessing themselves. Here’s Nate Silver at FiveThirtyEight trying to make sense of the latest poll numbers:
My horse sense is that the numbers are affected to some degree [by] response bias. Republicans, especially evangelical conservatives, are pumped now, after having been indifferent toward John McCain for most of the election cycle. They may be picking up the phone when a pollster calls when they had been screening out the call before, perhaps to the extent that they are biasing the sample. . . .
It seems plausible to me that some segment of conservative Republican voters had effectively been in hiding from the pollsters, either embarrassed by the performance of George W. Bush (and therefore disengaged from politics), or embarrassed to disclose to pollsters that they support him. Suddenly, with the selection of Palin, there has been a jolt of energy within this group, a release of pent-up frustrations, and they are coming out of the woodwork. If this is the case, then perhaps the partisan composition of the electorate had never shifted as much from 2004 as it has appeared to; rather, the conservatives were either reluctant to identify themselves as Republican, or reluctant to take a pollster’s calls in the first place. (Emphasis added.)
Never mind Silver’s guesswork about “response bias” — he is a 30-year-old baseball statistics buff and an amateur at political analysis –what’s noteworthy is how the Palin pick has punctured his heretofore insuperable confidence in his own predictions of an Obama victory in November. The marketers of Hope were always, at some level, dependent on their supporters’ notion of inevitable triumph. And the wild-card choice of Palin (and the conservative enthusiasm for her) has seriously undermined that notion.