For the last several weeks, I have been using statistical models to generate estimates for how likely each unpledged superdelegate was to vote for Hillary Clinton or Barack Obama. At last check (March 3rd), the models had successfully predicted the endorsements of 71% of the previously unpledged superdelegates. Thus, this model provides a reasonable way of getting a sense of which candidate the remaining superdelegates will favor.
Before I get to the new predictions, I want to update the information on how accurate this model has been. Since my last estimates, 17 superdelegates have announced their candidate endorsements and we predicted 11 of those correctly (65%). (All information on superdelegate endorsements comes from Democratic Convention Watch). Overall, since we began generating these predictions, 82 superdelegates have announced their endorsements, and we have been correct on 57 of these. Thus, overall, the models have been correct about 70% of the time. Below I have listed the most recent 17 endorsements.
I have updated the predictions for which candidate unpledged Democratic superdelegates are likely to support. As before, I use information about the superdelegates who have committed to a candidate to generate predictions for the remaining unpledged superdelegates. I exclude superdelegates from DC and the territories because we lack complete data from those areas, and from IL, NY, and AR because superdelegates in those states have nearly unanimously cast their support for their native son/daughter. As always, information on the superdelegates is provided by the Democratic Convention Watch site. You can find more about they methodology I use here. Check out the distribution of predicted support among unpledged superdelegates below.
Superdelegates who are between 40% and 60% likely to vote for Clinton/Obama are labeled as "unclear." There are 78 superdelegates in this range. There are 171 unpledged superdelegates who are at least 60% likely to vote for Obama; just 19 unpledged superdelegates are at least 60% likely to vote for Clinton. These predictions suggest that Obama will be able to cut into and even overtake Clinton's superdelegate lead in the coming weeks and months. Unless something significant changes, there seems to be little hope for the Clinton campaign in hoping that the superdelegates will help her erase Obama's lead.
The estimates for each unpledged superdelegate are listed here. These estimates show that among Obama's most likely endorsers are Governor Dave Freudenthal (WY), Rep. Dennis Moore (KS), and Rep. Tom Allen (ME). Clinton's most likely endorsers include Reps. Jerry McNerney, Susan Davis, and Lois Capps (all from CA).