Last week, New Jersey Governor Chris Christie scheduled the election to replace the late-Senator Frank Lautenberg for October, which — under state law — means that both parties must hold their primaries in August. So far, four Democrats have announced their bids for the vacant seat: Reps. Rush Holt and Frank Pallone, New Jersey Assembly Speaker Sheila Oliver, and Newark Mayor Cory Booker.

It doesn’t come as a surprise, given his huge name recognition, but early polls show Booker as the favorite for the nomination. According to a Quinnipiac survey released this morning, 53 percent of New Jersey Democrats support Booker for the nomination, compared to 10 percent for Holt and 9 percent for Pallone. Oliver wasn’t included in the poll — she announced over the weekend — but 23 percent remain undecided.

Even better for Booker is his high favorability rating. Fifty-seven percent say they like the Newark Mayor, while just a quarter say they don’t know enough to make a decision. Booker doesn’t have much room to grow with regards to favorability, but given his high ratings, he doesn’t need it.

All of this is good news for Booker, but it doesn’t mean he’s safe. Buzzfeed’s Ruby Cramer highlights the extent to which Booker isn’t loved in the New Jersey political establishment. The New Jersey Democrats who have lined up against Booker believe that he’s a showhorse — someone who hasn’t devoted the necessary effort to his job as Newark mayor, and instead has worked to build a national profile for himself, independent of his actual performance:

New Jersey political insiders said Democratic competitors will seize on the narratives that have persisted around Booker for years — that he spends too much time outside of New Jersey; that he is more popular outside the state than inside; that his record in Newark can’t hold up to scrutiny — and that they play up their longstanding relationships with the state party apparatus, which Booker has been known to challenge.

In defense of Booker, it’s hard to see how he could have avoided this. In general, African Americans have a hard time moving up the political ladder, and winning statewide office. This is especially true for black politicians who serve majority black constituencies; not only are they somewhat out of the political mainstream — on account of the particular interests of black voters — but they have a harder time fundraising and building a broader political base. It’s unfortunate, but opportunities are limited for politicians who are explicitly identified with African American voters. It’s why Barack Obama strays away from discussion of race. His blackness can hurt his political appeal (as was true during the Henry Louis Gates controversey) as much as enhance it.

All of this is to say that Booker’s ambition required him to immediately reach outside of Newark, and begin building the national image that could broaden his appeal and form the basis for a statewide run. And the irony of this, as Cramer details, is that it provides fodder for his Democratic opponents.

Of course, with a huge, 40 point lead over his competitors, it’s hard to see how Booker can lose. But it can happen, and if it does, it will be a product of the tough dynamic he finds himself in as an ambitious black politician.

Jamelle Bouie is a staff writer at The American Prospect, where he writes a blog.