Let’s first use CBO’s estimate of 4 percent growth. This is probably on the high side (CBO has been forecasting a surge in GDP just around the corner for five years now) so we’ll asterisk it as a high-end probability. President Obama’s job approval rating is -10.8 percent today. If we plug these two variables into [one of Alan Abramowitz’s forecasting models], it suggests that Republicans should be favored to win by about three points: 51.7 percent to 48.3 percent.
But, you say, with 4 percent growth, Obama is unlikely to remain at -10.8 percent approval. Fair enough. But even if we move him up to a net-neutral job approval, the models forecast a narrow Democratic loss, 50.5 percent to 49.5 percent. Obama would have to reach a net job approval of +6 before the model would forecast the Democrat to win (narrowly). Obama has accomplished this four times in his six years in office: During his two post-election “honeymoons,” after the shooting of Gabby Giffords, and after killing Osama bin Laden. If he ties his post-2009 best of +12 percent net approval, the model would favor the Democrat by a point.
Some important caveats:
These models aren’t the be-all/end-all of election analysis, and Republicans or Democrats probably could win under any of the scenarios outlined above. We also should remember that we’re building estimates on top of estimates here: Personal or national measurements of the economy could surprise us, pleasantly or negatively, and this would alter our estimates for 2016.
Regardless, these models probably can give us a rough sense of what would happen under various fundamentals for 2016. They point to a reasonably close election; they do not suggest that the Democratic nominee should be considered the favorite at this point.