It's a minor problem, as things go this week, but the @ column of Twitter has become nigh unreadable of late. Post a poll that doesn't look good for Mitt Romney, and off they fly -- conservative number-crunchers who point out that poll is hopelessly skewed because it shows Obama losing independents. Sometimes there's a quick reference back to actual 2008 exit polls; sometimes there's a reference, with a disclaimer that Dems will obviously never turn out at those rates again. On a conference call today, David Axelrod got a question about independent voters in Ohio and responded, matter-of-factly, that the campaign could win without them. My @ column filled up with people confidently saying that Axelrod was spinning a scenario in which Obama would lose.
Everyone should read Josh Marshall's quick post and helpful chart about what the "independent" vote means now.
The big thing is that independent identification skyrocketed and GOP identification plummeted in the Fall of 2010 — notably, this started just in advance of the 2010 midterm election.
Now, unless you assume that the US has moved strongly to the left since 2010, it seems pretty clear that what happened was an exodus from the GOP to the right. In other words, a lot of people left the Republican party, in identification terms. But they didn’t become Democrats. And it doesn’t seem (at least from the politics of the last two years) like they became more moderate of ‘centrist’ in ideological terms. They simply reidentified themselves as independents.
This is why it's possible for Obama to lose much of his "independent" gains from 2008 and still win. These clusters of independents are venn diagrams, not identical groups.