I'm on the side of the fence that says New Jersey is probably a waste of time for Bush. I imagine if he pushes hard here he could lose by 4-5% in November at the very best. (Unlesss something unforeseen happens, such as Giuliani taking over VP for Cheney, in that case we wouldn't need to worry about New Jersey because we would pick up most of the battleground states).
I don't trust Quinnipiac's poll or for that matter any poll conducted by a political science class at any educational institution. These people are amateurs in this business and they have no encouragement to perform well. Put your trust in solid private companies who need to be accurate in order to stay in business. Quinnipiac's track record is not very good.
I imagine the real number is around 8-10%.
Both CA and NJ are very tight this year, for special reasons that don't apply to other states. NJ was hardest hit by 9/11 (in proportion to size of state) and CA Dems have still not recovered from their disaster last October. Kerry will ultimately win both of those states, but he will have to spend money and time to secure them that he was hoping to spend elsewhere, which will help Bush.