I've noticed poll after poll that the Dems are being over polled, but however, Independents are also being under polled by large percentages and where Obama is losing the Indies by large percentages.
If this holds to be true, Obama is going to go down big.
http://hotair.com/archives/2012/09/16/can-obama-get-reelected-losing-the-independent-vote/
It probably would not be real inaccurate to believe the electorate is 1/3, 1/3, 1/3 and base polls on that ration.
However, as you not these are often 40-D, 33-R, 27-I or worse clearly an attempt to produce a lead for The Disaster.
Adding to this is refusing to poll likely voters exclusively.