That poll showing Barack Obama underwater in New York may not have been an outlier after all.  Quinnipiac finds Obama’s approval plunging neighboring — and nearly-as-blue — New Jersey.  While Chris Christie’s numbers have rebounded a little, Obama’s have slid to a new low:

President Barack Obama is headed in the wrong direction as New Jersey voters disapprove 52 – 44 percent of the job he is doing, down from a 50 – 46 percent positive score June 21 and the president’s lowest score ever in the Garden State.

Again, the gender gap is huge as men disapprove 60 – 37 percent while women approve 51 – 44 percent. Turning thumbs down on Obama are Republicans 93 – 6 percent and independent voters 57 – 39 percent. Democrats approve 77 – 17 percent. …

New Jersey voters say 49 – 45 percent that Obama does not deserve to be reelected, but say 45 – 37 percent that they would vote for Obama over an unnamed Republican challenger in the 2012 presidential race.

The independent vote is a big issue, although perhaps not in New Jersey as much as elsewhere. Democrats enjoy a large advantage in registration in the Garden State. In 2008, exit polls showed Democrats comprising 44% of the vote, compared to 28% for Republicans and independents alike.  Obama cruised to a 57/42 win in New Jersey while only getting a 51-47 split among independents — and a 14/85 among Republicans.

A big turnout of Democrats would still lift Obama to a win in New Jersey, but these numbers suggest that might be a little more difficult this time around.  Obama won Democrats 89/11 in 2008 when Hope and Change still filled the air.  He’s now down to a 77/17 in a deep-blue state — not bad, but indicative of a loss of enthusiasm.  That indicates a loss of turnout, and a big reversal among independents could make the race close in New Jersey.  That will have Democrats spending money in what is almost always a safe state on defense, which will prevent them from spending it in battleground states.

New Jersey would still be a long shot for Republicans in November 2012, but the sudden underwater status of his approval in two solidly blue states means that Obama will have to work harder than anyone thought necessary just to maintain traditional Democratic ground.

Update: This Survey USA poll in Portland, Oregon doesn’t bode well for Obama, either.  In a deep-blue West Coast city like Portland, Obama’s favorability rating is … 41/45.  Among independents, it’s 34/49, and it’s only 67/18 among Democrats.  Obama manages to be underwater among both men and women, too.