A new player entered New Jersey’s crowded polling market and confirmed the recent decline in Governor Christie’s approval ratings.  The big story of this poll is his possible slippage among independents voters.

The latest poll was conducted for Bloomberg news by Selzer  & Co, a well-respected Iowa polling firm with a pretty solid track record polling their home state’s hard to pin down presidential caucus.

The poll found Christie has an “upside down” job approval rating among all adults – 44% approve to 51% disapprove.  This is in line with the Quinnipiac Poll’s 44% to 47% results earlier this month and the Monmouth University/NJ Press Media Poll’s 47% to 49% result last month.

One of the first things I look for with new polls that differ from other findings is the partisan composition of the sample.  Unfortunately, not every pollster releases this – although any reputable pollster should have no problem including this important information with their poll results.   Fortunately, Selzer did include this data (for both their weighted and unweighted samples no less – kudos to them!). 

Their weighted sample of partisan identifiers (i.e. “In politics as of today, do you consider yourself a D/R/I?”) splits 30% Democrat, 24% Republican and 44% independent.  That 6 point Democratic advantage is a much narrower gap than most other polls show.  My tracking of the party identification question over the past year finds it hovering somewhere between a 12 and 14 point Democratic advantage – similar to the partisan split on the registered voter rolls.  If anything, this latest poll should be more advantageous to the Republican governor.

So why the big dip in Christie’s approvals when compared to Monmouth and Quinnipiac?

The biggest difference in the three polls is an apparent erosion of support among politically independent residents.  [Note: there is some danger in comparing sub-samples across different polls due to different question wording and weighting techniques, but the results bear watching.]

In Monmouth’s May poll, Christie garnered positive reviews among this important voting bloc by a decent 53% to 41% margin.  In Quinnipiac’s poll a few weeks later, this edge was a much narrower 47% to 44%.  The Selzer poll now shows independents evenly divided on the governor’s job performance – 47% approve to 47% disapprove.

There are some caveats for those concerned only with how this will effect Christie's re-election chances.  These polls sampled all adults or registered voters.  The Selzer poll does include a breakdown for those saying they are very likely to vote in this year's legistaive election.  But since this "likely voter" group includes 62% of all adults – as opposed to a more realistic 20-25% – it doesn't deserve much attention.  At any rate, it's too soon to predict who is likely to vote in 2013 when Christie is up for re-election.

It’s also important to keep in mind that all these polls were conducted before the governor’s pension and benefit victory and a poll next week could produce very different results.  [Although just released, the Selzer poll was actually conducted last week.]

 But the bottom line is that Christie’s job approval has been wavering – in spite of Piers Morgan’s claims* to the contrary during his obsequious CNN interview – and independents hold the key.

[*By the way, check out the Star-Ledger’s terrific new PolitifactNJ fact checking site.]