Beam: Lying About 2008?
Mark Blumenthal | June 19, 2009
Topics: Christopher Beam , Measurement , Retrospective vote questions
Slate's Christopher Beam notices an apparently extreme example of something common in political opinion polling. Winning candidates typically do much better in questions that ask respondents to recall who they voted for in the last election:
In the 2008 election, Obama won 53 percent of the votes; John McCain got 46 percent. But two new polls, conducted by the Wall Street Journal/NBC and the New York Times/CBS, show Obama winning by a much wider margin.
When respondents were asked by the WSJ whom they voted for in the 2008 presidential elections, 41 percent said they voted for Obama, compared with 32 percent for McCain. Factor out the 18 percent who said they didn't vote, and you've got Obama beating McCain by 11 points, 50 percent to 39 percent.
The gap in the New York Times poll is even wider. In it, 48 percent of respondents said they voted for Obama, compared with 25 percent for McCain. Again, subtract the 19 percent who say they didn't vote, and you've got Obama winning by a nearly 2-to-1 margin, with 60 percent to McCain's 32 percent.
This sort of discrepancy is not unusual, as Beam reports and as evidenced by an old MysteryPollster post that he links to. Still, he catches what appears to be an unusually large gap:
[T]he disparity between declared Obama voters and actual Obama voters is especially wide. The gap is usually in the single digits, and it waxes and wanes with the president's popularity. The New York Times poll, conducted periodically since Obama's inauguration, shows the gap between Obama and McCain steadily growing. In February, he led McCain 42 percent to 28 percent. In April, it was 43-25. By June, his lead had grown to 48-25. "Even by the standards of historical numbers, that's a large gap," says Adam Berinsky, a political science professor at the Massachusetts Institute of Technology.
Beam does a good job explaining the likely reasons for the gap, and I recommend reading it in full (though full disclosure: he interviewed me for the piece via email).
By Mark Blumenthal | June 19, 2009 4:24 PM | Permalink | Comments (0) | TrackBacks (0)
