I was discussing in good faith, so I'm not sure why you chose to be snarky. Let's clarify here, I'm not sure what "sampling error" in this case would be, such that it is distinct from electoral trends at large. The random variables in question _are_ demographic groups. How is it meaningful to discuss sampling error if your assumption is that state and county data is independently distributed? The poll data that Gelman et al used is public data, I urge you to take a look and work with it.