When recent polling from Steve Lonegan’s campaign suggested that the Republican had moved within the margin of error of massive favorite Cory Booker in next month’s race to fill the rest of the term of late US Senator Frank Lautenberg, I was highly skeptical. I’m generally suspicious of polls released publicly by campaigns anyway, and in this case especially so. Despite Chris Christie’s big successes in New Jersey, it’s still a blue state, and Booker has been a popular mayor in a big media market.

At least, I was skeptical — until today.  The New York Times reports that Booker’s backers have started to get nervous, and now Michael Bloomberg will dump $1 million of his own cash to rescue Booker:

Cory A. Booker is an undisputed star of a new generation of African-American leaders, electrifying liberal audiences with his oratory and charming the social media set with his digital savvy.

But the Senate campaign Mr. Booker, a Democrat, is running in New Jersey — at times sputtering, unfocused and entangled in seemingly frivolous skirmishes over Twitter messages involving a stripper — has unnerved his supporters, who thought that a robust and unblemished victory over his Republican opponent, Steve Lonegan, would catapult him onto the national stage.

As his allies move to shore up what was supposed to be a painless path to Congress, the biggest and wealthiest of them, Mayor Michael R. Bloomberg, will start spending more than $1 million on Monday to broadcast television commercials on Mr. Booker’s behalf, a vast sum to pour into a single candidacy. …

Mr. Lonegan, despite his ideological alignment, appears to have tapped into lingering doubts about whether Mr. Booker can translate his outsize, self-promotional persona, so popular with the Democratic base, into the rigors of a highly disciplined campaign. …

A radio commercial hammered Mr. Booker, 44, for traveling to the West Coast a few weeks ago to attend a fund-raiser with Matt Damon and Ben Affleck after murders had spiked in Newark, declaring: ”While you’re listening to this ad, Cory Booker is in California, getting as far away as he can from his own city’s problems.”

Don’t get too excited, though. A follow-up poll by Monmouth University released last week showed Booker up by 13 points, 53/40. The week before, a Quinnipiac poll showed Booker up 12 points. The problem for Booker’s supporters is that this isn’t a big enough lead, considering the relative standing he has against Lonegan in the media and in the state.

That should be a worry for Booker, who tried to paint himself as a uniter in yesterday’s debate.  He told audiences that Lonegan would only add to the forces in Washington that have created the government shutdown, while noting just how well he works with Christie to keep the state in business. On the other hand, even some of his supporters wonder exactly what Booker actually did as mayor of Newark:

In interviews, even those who said they planned to vote for him expressed reservations about his experience and ambitiousness, arguing that he had not yet truly proved himself in Newark.

Kenneth Paige, a 54-year-old barber in East Orange, where Mr. Booker campaigned over the weekend, cited the continued problem with crime in Newark.

”What did he really do?” said Mr. Paige, a Democrat, who indicated that he would vote for his party’s nominee nonetheless.

Can Bloomberg’s bucks keep that question from popping up? Probably not, but Lonegan has a very long way to go and a very short time to get there — and that million dollars will create even more headwinds.