"I'm not sure that I would have predicted the pattern we actually observed, which is Democrats being more likely to over-attribute to Obama," said J. Mark Hansen, a political scientist at the University of Chicago. "My speculation is that it's largely motivational. That, like everybody else, the Democrats remember that Obama did something in these areas, and most of what they're doing is guessing as to who did what."
Mr. Hansen, who collaborated on the study, said the findings suggest politicians should be wary of reading too much into specific election mandates, saying that in both polling and elections, "voters are sending a pretty noisy signal about what they want."