Exit Polls 101

Exit polls out of North Carolina suggest that Obama has won the state by about 14 percentage points. While CNN does not report the overall percentages for each candidate, we can divine them by weighting the demographic breakdown between the candidates by each demographic’s turnout. For example, here’s the exit poll data for gender :  

Clinton Obama
Male (43%) 40 56
Female (57%) 42 54

From here, we deduce:

Clinton = (40% of males) * (43% male voters) + (42% females) * (57% female voters) = 41 percent of the vote

Obama = (56% of males) * (43% male voters) + (54% females) * (57% female voters) = 55 percent of the vote

We can do this for any of the exit poll categories and we’ll get similar results.  

Accord to Slate ’s Delegate Calculator , a 14-point win for Obama in North Carolina will grant him a 66-49 advantage in pledged delegates in the state for a net gain of 17. Clinton netted 12 pledged delegates in her nine-point win in Pennsylvania, though it’s worth noting that the estimates of pledged-delegate leads are more likely to shrink than grow as the results from individual districts are reported.

If, however, Obama does end up posting a win in North Carolina of this magnitude, he is well positioned to at least cancel out the progress in delegates Clinton made in Pennsylvania.