Swings that radical, if the initial sampling is accurate in terms of size and randomness, are unusual but not out of the realm of possibility. My expectation was that those numbers would become more favorable to Sanders, not less. Sanders won rural upstate 58-42. Polls in rural upstate opened at noon, six hours later than polls in Buffalo and downstate, and just a handful of hours before initial exit polling was released. In Wisconsin, where I watched exit polling shifts carefully, younger voters voted later and stretched results more in Sanders favor.
I wanted to see what the initial sample size was. What I found was rather shocking.