Pew just released a new poll showing a dropoff in President Obama's approval. The New Republic's Nate Cohn crunched the numbers and found the decline concentrated in one subgroup in particular:
Today's Pew Research poll paints a clear picture of the Obama defectors. They're almost exclusively white voters without a college degree. Obama's standing among minorities, college educated whites, and affluent whites has actually improved since the final Pew Research poll before last November's presidential election. Instead, Obama's support among white working-class voters has taken a huge hit, opening an unprecedented 41 point education gap among white voters....Or maybe it is. The George Zimmerman verdict came down on July 13. The Pew poll was conducted July 17-21, when the verdict was being denounced as racist by many African-Americans and, well, many college-educated whites.
The source of the collapse isn't clear....
In fact, Pew's poll on the Zimmerman verdict -- which showed a big racial divide -- was conducted at exactly the same time, with exactly the same sample size. So I have to assume the two polls were one large poll.
I don't know what the order of the questions was, but it's generally recognized that early questions in a poll can influence answers on later questions. If bad feelings among non-college-educated white respondents were stirred up by Zimmerman questions, it seems possible that their answers regarding our first black president might turn a bit more negative.
So maybe this poll is just a snapshot of the post-verdict moment, not a sign of a larger trend.