Cross-posted from Blue Jersey under a different title. Apparently, there is DKos history I wasn't aware of that I'd rather just avoid.
This graphic, based on the poll tracker at Talking Points Memo, shows Chris Christie's favorables and unfavorables over his term as governor. I've added, in blue, several key events from this period to give some context as to why his numbers may have varied.

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Notice that Christie's three largest legislative accomplishments -- 2% Cap, Pen-Ben, and TEACHNJ -- have little if any positive effect on his favorables. I would argue there are only two big bounces: post-Irene, and post-Sandy. What does this mean?
Without natural disasters, Chris Christie's re-election chances would be much lower than they are right now.
Which means the presumed front-runner in the presidential race of 2016 does not have a lock on winning by a "bigger margin than any Republican in a generation." And he knows it, which is why he has set his sights far lower in recent months.
So Christie is mortal; in fact, I believe he can be beat. I believe this week's news that his lead over Barbara Buono has shrunk was inevitable; with a big push by Democrats and smart campaigning by Buono, that lead should, inevitably, shrink even more.
Given all this, you would think our lame-duck president -- who has nothing to lose in supporting Barbara Buono -- would make at the very least a cursory showing of support. You'd think Barack Obama would show just a little effort and enthusiasm for the only prominent Democrat in New Jersey who had the guts to take on the challenge of running against Christie. Out of respect to her, the state party, and all the people Christie has slimed over this last term, you'd think our "fightin' for you!" president could take a few hours to get on a plane and stand side-by-side with Buono, lending a fraction of his star power in the cause of at least slowing Christie's charge at the White House.
You'd be dead wrong:
President Obama is not planning to campaign for Democrat Barbara Buono in her quest to rob Gov. Chris Christie of a second term, the Associated Press reported yesterday.
This year and next, Obama only plans to lend his political firepower to close races where he could help cinch a win for his party, a Democratic official involved with Obama’s political plans told AP. The official wasn’t authorized to discuss strategy and requested anonymity, the wire service said.
Why?
Why would Obama do this?
It's the type of delicate, race-by-race calculation the White House repeatedly will have to make in the 2014, when Obama's own legacy will be on the line. Next fall, voters will decide whether to elect a Congress that will help Obama achieve his goals for his final two years in office, or whether to elect one that will block him at every turn.
You're worried about your "legacy," Mr. President? Well, here's your legacy, at least in New Jersey:
You're dead to me. You're dead to every teacher Chris Christie insulted over these past four years. You're dead to every public employee Christie broke his promises to. You're dead to every gay and lesbian couple and their families who want marriage equity. You're dead to everyone in this state worried that our environment is being raped. You're dead to every woman seeking health care. You're dead to the middle class families who suffer under Christie's inept stewardship of our state's economy. You're dead to the students and parents who have to live with the consequences of Christie's refusal to adequately fund our schools. You're dead to those who will pay the price for Christie's politicization of our courts.
President Obama, by refusing to back Barbara Buono, you're dead to everyone who is appalled by Chris Christie's unrelenting assault on the values that made this state great.
If, Mr. President, you can't even muster up a shred of your time and your "legacy" to support Barbara Buono, then I say the hell with you.
ADDING: More from vmars.