I saw the polls for the Super Tuesday southern states back in 2008. Besides Insider Advantage all the other outfits (including PPP) screwed them pretty badly. I remember they were showing McCain winning comfortably Georgia and Alabama when in reality he lost them to Huckabee.
Can someone explain to me why the Deep South is so difficult to poll?
No party registration is the most likely culprit, in that a lot of rural voters still identify as Dems, and might get knocked out of the sample.
That being said, Huckabee was from the South, Newt is, and Santorum isn't. In case we haven't forgotten.