New Farleigh Dickinson University Public Mind poll (June 17- 23, 702 RV, MoE +/- 4%), has Obama up by a comfortable 16 points in the Garden State:

Obama 49
McCain 33
Undecided 15

Obama leads by 10.3% in the RCP Average for New Jersey.

From the write up:

However, the results are not all good news for Obama. Only 64% of respondents who say they voted for Sen. Hillary Clinton in February's primary election now say that they will support Obama in November; 18% say that they will support the Republican. "In many ways, this race is going to be a fight over Clinton supporters," said Dan Cassino, a professor of political science at Fairleigh Dickinson and survey analyst for PublicMind. "That fight is far from over."

However, hurting McCain is the fact that only 18% of voters say that they approve of the job President Bush is doing while 75% disapprove. Worse, only 15% say that the country is moving in the right direction and nearly three in four say the country is headed in the wrong direction.