His job approval and favorable rating are still net positive — amazing resilience, really, for a Republican dogged by scandal in a blue state — but the gap is closing. Polls taken earlier this month in Jersey after Bridgegate broke showed minimal damage to him; this one, from the Eagleton Center at Rutgers, shows that it’s now more severe. And this one was mostly conducted before the mayor of Hoboken accused him of withholding Sandy aid unless she approved a development project in which Christie was interested.

It’s hard to be “the electable candidate” if you’re not much more electable than your rivals. Christie’s not sunk yet, but if independents start to bail, hoo boy.

Following more than a year of strong bipartisan support, Christie’s favorability rating is now 46 percent favorable to 43 percent unfavorable, down from 65 percent favorable just before his landslide re-election. This drop in support is led by a 26-point decline among Democrats…

Christie’s ratings drop is driven by a very large decline among Democrats while most Republicans – and many independents – continue to stand by the Governor. In November, 45 percent of Democrats were favorable, but with new challenges to Christie’s bipartisan leadership, only 19 percent of Democrats are now positive. Democratic approval of Christie’s job performance has dropped from 51 percent to 29 percent. While noticeably down from November, Republicans are still very positive: 78 percent feel favorable, and 83 percent approve of the job Christie is doing. Independent support has also dropped, but a majority continues to favor Christie…

[O]nly a quarter of Democrats think Christie was unaware of his aides’ actions; instead, over half say it is very unlikely Christie was out of the loop. Moreover, 62 percent of Democrats do not believe at all Christie’s explanation for what happened.

Whether or not they think Christie is telling the truth, New Jerseyans overwhelmingly blame Christie’s “tough-guy” persona for the conduct of his staff: more than 70 percent say the Governor’s attitude contributed at least somewhat to his staff’s reported behavior. Even six in ten Republicans believe Christie’s demeanor has at least somewhat encouraged these events.

Nine days ago, Monmouth had his job approval at 59 percent and his favorable rating at 44/28. Today Eagleton has them at 51 percent and 46/43, respectively. Among Democrats, it’s a bloodbath — they disapprove of his job performance overwhelmingly, 29/64, and view him unfavorably even more overwhelmingly at 19/69. You can, if you like, ignore that decline as inevitable: Just as Hillary’s sky-high bipartisan favorable rating has begun to sink now that it’s clear she’s the prime threat to the GOP in 2016, Christie’s support among Democrats would surely have sunk over time once he ran for president. All Bridgegate’s doing, arguably, is accelerating the process. Problem is, the acceleration hurts his big presidential pitch that he can get Democrats and indies to cross the aisle unlike anyone else in the GOP field. It’s fine for Democrats to turn on him but he’d much prefer that to happen later, after he’s got the nomination in hand. As it is, he now trails Hillary in New Jersey by 21 points — which, per Harry Enten, is actually a bigger deficit than Mitt Romney ended up with there against Obama in 2012. If that doesn’t change substantially before the GOP primaries, how does a guy who’s underperforming the previous nominee in his own state against a non-incumbent make the case that he’s Mr. Electable?

There’s always a chance Christie will rebound, but here’s an eye-popper from Eagleton suggesting why he won’t:

It’s a legit achievement for any blue-state Republican governor to stay at or around 50 percent approval for years on end but the legend of Christie’s allegedly unique bipartisan appeal is, obviously, mostly a product of Sandy. His numbers took off after the storm and now Bridgegate’s returned them to their pre-storm normal. How likely is it that he’ll give New Jersey Democrats a reason to start nudging them back up towards 60, especially once they’re eyeing him as an obstacle to holding the White House in 2016?

The keepers of the flame now are independents and moderates. The former currently split 60/33 on Christie’s job approval and 55/33 on his favorability; the latter split 53/40 and 45/41, respectively. As long as those numbers stay healthy, he can still make the “I can play on Democrats’ turf” argument. As for Latino and black voters, whom Christie took care to woo before the election to further polish his crossover cred, I’d love to give you the data but I can’t. Eagleton, oddly, didn’t provide it for those groups. For what it’s worth, the anecdotal evidence looks favorable to Christie. Stay tuned.