More than half of Americans don't believe New Jersey Gov. Chris Christie when he says that he didn't know about his staff's role in shutting down access to the George Washington Bridge. And, unlike in his home state, they're mad about it.

Change in percentage viewing Christie unfavorably since Jan 2013

A poll conducted by Pew Research in conjunction with USA Today has the first national overview of the political ramifications of the bridge scandal. For a Republican who wants to run for president in 2016 on the basis of his ability to work with Democrats and independents, the numbers couldn't be worse. At right, how opinions of Christie changed by party and region of the country since last January. While his favorability generally only dropped slightly, his unfavorability among every group increased, often out of the pool of people that had no opinion of him previously. If Christie wants to make his 2016 case based on the idea that he can win Democrats and the northeast in a general election, these numbers make that pretty difficult.

Most interesting is that people simply don't believe that he wasn't aware of the plan to close lanes leading from Fort Lee onto the bridge, which emails show was OK'd by Christie's deputy chief of staff. Only Republicans are more likely to think he didn't know than that he did — but fewer than half give him the benefit of the doubt. Independents are twice as likely to assume Christie knew about the closures as not; Democrats, three times more likely to be skeptical.

It's very possible that this perception follows from the now-cliched comparison of Christie's administration to The Sopranos: Who would believe that Tony Soprano doesn't know what Uncle Jun is up to? Or, perhaps, it stems from a brief familiarity with Jersey politics. The mayor of Hoboken who over the weekend introduced a new wrinkle to the scandal herself only came into the position after her predecessor was arrested three months into his tenure. During that 2009 bust, a number of other politicians were also taken into custody.

Which may be why people in Jersey were actually less likely to have a diminished assessment of Christie. A poll from Monmouth University shortly after the initial revelations came out show that people in the state still had a high opinion of Christie, though they agreed that he likely knew about what had happened before getting a phone call from a staffer during his workout earlier this month.

The only good news for Christie is that Republicans are holding fairly steady in their support. Only Tea Party Republicans saw their opinion of him drop much since a year ago — and that may in part be due to his explicit effort to be considered a moderate. If Christie is exonerated in the bridge scandal — which is possible — his numbers with other groups could rebound. If he isn't, a 2016 bid seems pretty optimistic.