The biggest shift in Ohio is in the southern Ohio coal belt. 55-45 for Obama in 2008, now 60-40 for Romney. The statistical models on which the statewide polls are designed are not recording this big change.
I can believe it but the area is not the heaviest population unfortunately. There will also be a dropoff in black turnout in the cities, which may or may not be factored in. Such changes are going to be real but difficult to predict numerically.