Obama needs to poll constantly above 50% because they will break hard for McCain.
That's my suspicion, especially in NC/VA.
THey didn't in 2004 the went to Kerry.
The last minute deciders broke to Kerry, but that's to be expected against an incumbent. The polling suggested a Bush victory of 8% or so and he won by 13%. I know the polling was within the margin of error, though. Obama very well may win North Carolina, but if he's still polling under 50% then his chances become slimmer. At this point I'd say Virginia is lean Obama. NC is still a tossup or slight Obama.