Cory Booker may be "America's favorite mayor," but in New Jersey, his fast rise and transparent ambition has rankled many establishment Democrats, who suggest he's putting himself above his state party.

The Newark Mayor's December announcement that he'd "consider" a Senate bid in 2014 — a decision that followed a long, public deliberation played out on Sunday shows and cable news — may have served to raise his national profile. But Democratic insiders complain that it upended the state's political landscape, making Republican Governor Chris Christie, without Booker challenging him, a virtual lock to win re-election, and setting in motion an intra-party war that has the state choosing sides between Booker and the 88-year-old incumbent Senator Frank Lautenberg.

Technically, Booker says the Senate bid is only a possibility, but N.J.'s political class knows better.

By the morning of Booker's video announcement, the call to supporters was already out and a political action committee was poised to send an e-mail blast to 75,000 potential Booker-for-Senate donors — "Cory Booker is running for Senate,” the email said. The group, PAC Plus, now plans to contact 500,000 supporters over the next month, with a goal of raising $100,000 for Booker by June, director Steve Phillips told BuzzFeed.

The Senate run that Booker said he would “explore” — a “possibility,” he called it in his announcement video — was in high-gear from day one.

As a N.J. Democratic official put it, “Booker is running — that’s the bottom line.”

“No one in the state ever thought he was running for governor,” said the official. “That was all bullshit. Christie owns him, but he was really being pushed by other power brokers in the state who are much more concerned about the down-ballot effect of what could potentially be a slaughter in 2013.”

Even before Booker said he wouldn't challenge Christie for the governorship, the chances of any Democrat taking on the incumbent seemed grim. The governor's approval ratings went as high as 77 percent after Hurricane Sandy.

But with Booker out of the gubernatorial race, the chance of a major thumping in 2013 is all the more likely. The party has yet to rally behind a single candidate, in part, sources say, because the bench players had to wait on Booker’s decision before they could get in the game themselves.

Already late in the race, only one Democrat — progressive state Senator Barbara Buono — has officially declared herself a contender. Other possible Democratic candidates include Rep. Bill Pascrell, former N.J. governor Dick Codey, and state Senate president Stephen Sweeney, who received a call of encouragement from Booker himself last month.

New Jersey state Senator Loretta Weinberg told BuzzFeed she’d personally tried courting Booker for a gubernatorial run as early as the Democratic National Convention in September to avoid the disparate field with which the party is now coping.

She wasn’t the only one, either. In the Charlotte hotel where New Jerseyans set up camp for the DNC, the bar was host to private confabs between state officials. “You could see all the grand poobahs in the Democratic party meeting with him,” Weinberg remembered. “We thought Booker would be an excellent candidate.”

Weinberg said she'd given the mayor some advice: "In politics, you’re usually better off going to the position that’s offered to you, not necessarily the one you want two years from now, because they’re not necessarily mutually exclusive.”

But when it became clear that Booker was leaning away from the governor's race, Weinberg would make a public plea to Booker — an open letter on bluejersey.com. “The state needs you and our party needs you,” she wrote.

Ten days later, on the morning of the announcement, Weinberg got a call from Booker with the heads-up — he wasn’t going to be taking her advice.

The big problem, though, was that Booker “took a long time to make his decision and was inappropriately agonizing over it,” said Weinberg. “I’m not angry, I’m disappointed. And I don’t think it was handled in the most appropriate way because it took much too long.”

Democrats are desperate, said Weinberg, to regain control of the New Jersey governorship, considered one of the most powerful of any state in the country. By law, Christie has the authority to traditionally veto, outright veto, or rewrite any piece of legislation and send it back in a different form to the Democrat-controlled state Senate.

“The longer we take and the less unified we are, the harder it’s going to be,” she said, referring to the governor’s race this fall. “We’re very anxious now as a party to rally around our candidate whoever it will be. The sooner it will get through this, the better it will be for the party.”

The party is also faced with the uncomfortable dynamic Booker’s Senate race has created surrounding Sen. Frank Lautenberg, one of the most respected, storied figures in the state’s political history, who also happens to be 88 years old and hell bent on staying in office — or at least retiring on his own terms.

Although Lautenberg would be 90 years old in 2014, running a re-election bid for a six-year term, he has not publicly indicated even the impression that he wants to retire.

Lautenberg did retire once before in 2001, but he was asked a year later to unseat an incumbent candidate, Sen. Bob Torriecelli, after he was charged with federal corruption. But Lautenberg’s respite from office was a decision he is said to have regretted within minutes of making.

Although Lautenberg’s office received advance warning of Booker’s announcement, a N.J. Democrat said, the Senator was offended that his retirement should be anyone’s decision but his own.

Booker chose his words on the subject carefully in the video announcing his Senate run. "I forward to consulting with Senator Frank Lautenberg,” said Booker, adding that “it would be a privilege and honor to continue his legacy of service."

Booker also tweeted hours later that Lautenberg “has served NJ well. Right now I’m going to talk with him,” he wrote.

But Booker wasn't waiting around for Lautenberg to make up his mind. The mayor was already on Twitter, rallying the troops. “So happy to hear of your plans to run for US Senate,” said one supporter. Booker’s response — “Thanks! Please register at corybooker.com.” Another supporter, on the day of Booker’s announcement: “Caught up on the news of today. Cory Booker has my vote.” The response from Booker again — “Please register your email at corybooker.com.” Ten more such tweets exist on Booker’s feed.

A day after the announcement, Booker told NBC Channel 4 that he personally had “not been able to connect with the Senator.” That same day on NJTV, when asked about a potential primary race against Lautenberg, Booker responded, “That hypothetical question is inappropriate right now. Let me afford him the respect of hearing what his thoughts are and what he wants to do. He hasn’t commented on that yet.”

(Lautenberg, meanwhile, had issued a response. The day before, the Senator’s spokesman Caley Gray released a statement to the press: “This is not the time for political distractions and the Senator will address politics next year,” said Gray.)

Booker should have shown more deference to Lautenberg, Weinberg said, but added that “it’s very difficult to find language that covers both sides of the coin — the respect for Senator Lautenberg, and also the plan to run.”

One N.J. Democratic official said Senator Lautenberg’s decision about 2014 won’t be swayed by Booker’s announcement. “The analysis about respect and disrespect — it doesn’t matter, Booker is running, and Lautenberg will have to make his own decision,” said the official.

“It’s up to Senator Lautenberg,” said Weinberg. “Frank Lautenberg has earned the right to make this decision in his own time and in his own place. He is still our Senator.”

Weinberg indicated that if Lautenberg did put up a primary fight, the majority of the state party would support him over the Newark mayor. Senate Majority Leader Harry Reid said as much on the day of Booker’s announcement. “I always support incumbent Senators,” Reid said. “I would always support Lautenberg or anyone else that’s up for reelection.”

In 2008, Lautenberg faced a similar, if not more confrontational, challenge to his seat from Democratic Congressman Robert Andrews, who openly gestured toward Lautenberg’s age during his campaign for the nomination.

Lautenberg, then 84 years old, retained the support of Governor Jon Corzine and the state county chairs.

But one powerful New Jersey Democrat said Lautenberg wouldn’t enjoy the same level of backing this year, were he to run for another term.

“The support that Frank Lautenberg had when Rob Andrews ran against him four years ago and brought up the age issue that offended so many people wouldn’t offend those supporters now,” said the source. “With Chris Christie in office, able to appoint a Republican successor, it would be a completely different situation.”

But even if state Democrats rally behind the Lautenberg camp, the Senator would face a bitter primary fight. A poll released in late November by Public Policy Polling showed Booker leading Lautenberg in a theoretical primary by a 59-22 percent margin.

A third potential contender for the Senate seat, Congressman Frank Pallone, is “all but certain to run for Senate if Lautenberg retires in 2014,” according to a report by Roll Call.

But the difference, the N.J Democratic official told BuzzFeed, is that Pallone has long showed Lautenberg the deference that the senior Senator so values. “Pallone handled it in a way where it’s always been clear that he would only run if Lautenberg retires. He’s been saying that for years.”

“The real question is, will Pallone hypothetically let Booker step into the seat, or anybody else,” said the official. “Open Senate seats don’t come around often, and he’s been waiting his turn patiently.”

Democrats in the state know that if Lautenberg is offended enough, he may step out of the race only to endorse Pallone, a candidate more likely to spend decades in his Senate post — in the tradition of Lautenberg — rather than Booker, who might make another pass at governor or go all the way to the White House.

But a potential primary between Lautenberg and any candidate, the Democratic official said, would be “a super-contested and messy race against a Democratic legend.”

In short, a bad look for New Jersey.

Lautenberg, who will likely have to make a decision before June of 2013, is a fighter and "he's not gonna be boxed out of a fight," said the official. "Booker is running — it is what it is. And Lautenberg will make his announcement when he's ready. No one is counting him out — anybody in New Jersey politics would be crazy to count Lautenberg out.”