Public Policy Polling for Daily Kos and SEIU (5/12-15, MoE: ±3.1, registered voters, Obama trendlines 5/5-8, all others 4/28-5/1):
Last week, I asked whether the rise Barack Obama saw in his poll numbers due to bin Laden would "prove enduring or ephemeral." I still think it'll be a while before the verdict is in, but for at least one more week, the president's job approval remains where it was right after the bin Laden news was announced. You can see the trendlines using this cool new tool developed for us by
Tableau Software:
As an aside: The Tableau visualizations are available for every question we ask in our polls (whether it's Pelosi approvals, Obama favorables, etc.) and will soon be embeddable.
So where is this bounce coming from, and what's sustaining it? Our pollster Tom Jensen opines:
The last couple of weeks of this poll are a poster child for not weighting for party. I’m sure some folks are going to say we’re showing better numbers for Obama because we’re polling too many Democrats but I think the reality is that when people like Obama they’re more likely to identify as Democrats — and that polls that weight for party are probably keeping his numbers artificially low during this bounce period.
In other words, some voters are simply the electoral equivalent of "fair weather fans," who root for Democrats (or Republicans) when that side is doing well. Unlike most of the other demographic questions we ask — gender, race, age — people can pick and choose their party ID. If you decide in advance what proportion of the electorate "should" be Democrats, then, as Tom says, you're going to miss out on these softer supporters who are apt to change their minds. To put things numerically, here's the party breakdown for our last three polls:
43 D, 33 R, 24 I
42 D, 32 R, 27 I
38 D, 32 R, 30 I
Osama's death was announced between the second and the third polls on this list, so you can see precisely where the Democratic jump happened. (And it also involved, as you might expect, independents migrating toward Team Blue. Republicans have held perfectly steady.) This trend may not last, but while it's happening, it's a real phenomenon — other pollsters have found it as well, but those who weight too aggressively miss it at their peril.