At FiveThirtyEight, we generally prefer state polls to national polls. So far, though, we haven’t had much of them to work with. If you’re getting dozens of national polls every week, but just a smattering of state-level surveys — and that’s what we’ve been getting — you’re better off inferring what’s going on in the states from the trend in national polls, rather than the other way around. …
On Tuesday, we finally got a bunch of state polls to test the theory — three polls each from Quinnipiac University and Marist College. And, in fact, the new data mostly confirms our hypothesis, although with some caveats. CONT.
Nate Silver, FiveThirtyEight