Sean Trende at Real Clear Politics has written an ambitious new post arguing that the state of the economy is not necessarily "principally responsible" for President Obama's approval ratings, pointing to posts by Jon Chait (citing me) and Ezra Klein:
There is no doubt that, as a general matter, the economy is an important factor in driving a President’s approval (this is also true for midterm elections, see my writing here). But it is far from clear the economy is what is principally responsible for driving down President Obama’s approval rating and engendering a Democratic debacle in the fall...
Obama’s approval ratings are almost certainly influenced by economic conditions. But a controversial energy bill, a prolonged, contentious fight over health policy, and yes, even a “snakebit” response to the oil spill, have had a substantial effect on the President’s approval ratings. If missteps continue, it could make the difference between a bad and awful midterm election for the Democrats.
Trende projects Obama's approval ratings using a statistical model from a 2002 article (gated) by Brian Newman that I sent him and compares what they would be under various scenarios he constructs -- in particular, a no-events scenario, a negative events scenario, and a positive events scenario (see his post for details), which result in the following projections:
Trende notes that the second graph seems to match observed approval ratings better than the first, and claims that it suggests the negative public reaction to Obama's agenda and oil spill response drove down his approval ratings relative to the state of the economy. That's certainly possible, though it's not clear at this point. First, there are many possible explanations for the difference between the economics-only model projection and Obama's observed approval ratings. Second, it's not clear for how long the predicted values from the two models are statistically distinct -- Trende's graphs show that they both converge to Obama's observed approval ratings in recent months. And finally, Trende's model may not the correct one. For instance, as he acknowledges, an alternate model matches Obama's approval ratings quite well using only economic factors.*
More generally, Trende's target is unclear. Both Chait and I have mocked Obama critics who fail to acknowledge the dominant role of the economy in presidential approval, but we have each made clear that we believe events influence presidential approval. The fact that Obama's approval apparently deviated from its projected economics-only trajectory for some length of time does not disprove those claims. At best, it comes down to a subjective judgment about what being "principally responsible for driving down President Obama’s approval ratings" means.
Trende specifically criticizes Chait for this passage, which was written on July 1:
Right now, President Obama's approval rating is hovering just below 50%, about even with his disapproval rating. Given the state of the economy, that's not low. (I don't have any models handy.
However, Trende's economics-only and negative events models (the first and second graphs) show very similar values in the most recent period -- the difference may not even be statistically significant. As such, Chait's statement is likely to be an accurate one by the standard of Trende's post. Though Obama's approval may have declined faster than we would have otherwise expected, it's not currently especially low given the state of the economy.
* I'm not sure how relevant Trende's third graph is -- very few modern presidents have had such a positive experience during their first two years in office. As I noted a month ago, only two presidents of the last seven have had approval trajectories substantially more positive from Obama's thus far (Bush 41 and 43), and one of those was the result of an unprecedented terrorist attack on America. In any case, the fact that Obama's approval could have been higher in a counterfactual scenario doesn't prove that events are depressing his observed approval ratings.