Heh. The PPP poll was done as a sanity check against the SUSA poll.
http://tpmelectioncentral.talkingpointsmemo.com/2008/09/new_poll_finds_mccain_with_nar.php
-Yes, I saw the poll with McCain up 20 in North Carolina.
-No, I don't believe it.
-Yes, we are going in the field tonight.
The difference between the two:The key difference here is party identification. SurveyUSA's numbers had self-identified Dems making up 40% and GOPers at 41%, roughly in line with the 2004 exit poll. PPP's numbers have Dems at 49% and Republicans at 36%, seemingly consistent with an overall increase in Democratic registration and identification across the country over the last four years.
The only way to settle the question of which party ID breakdown is right is to wait for the actual voting.
http://tpmelectioncentral.talkingpointsmemo.com/2008/09/new_poll_finds_mccain_with_nar.php