TRENTON — State Sen. Barbara Buono today announced she's running for governor, becoming the first high-profile Democrat to launch a campaign aimed at toppling popular Republican incumbent Chris Christie next year.

"It’s time for a leader in Trenton who will put the middle class first — lifting our schools instead of scapegoating our teachers; protecting property taxpayers rather than pushing income tax cuts for millionaires," Buono (D-Middlesex) said in a email message to supporters.

Buono’s announcement comes as New Jersey’s political world awaits word from the Democratic Party’s biggest name: Newark Mayor Cory Booker, who said he will decide whether he’s running for governor within the next two weeks.

While Buono is in the race, other high profile candidates will likely be scared off by a Booker candicacy. If Booker doesn’t run, Buono could face a crowded field of challengers, including her bitter rival, Senate President Stephen Sweeney (D-Gloucester).

Once entrenched in party leadership, the 59-year-old lawyer has repeatedly butted heads with top Democrats as they embraced elements of Christie’s agenda, including shifting greater health and pension costs onto public workers. That means that while she may get the support of public worker unions, Buono faces an uphill climb in a state where primaries are often won or lost based on support from county parties and power brokers.

"I’m not going to run a conventional campaign," Buono said in a three-minute video message that accompanied her announcement. "And I won’t be anointed by the political bosses. Instead, I’ll stake my chances on the folks at grocery stores and train stations"

Buono, a native of Nutley who has lived in Metuchen for decades, has the inside track in her home county of Middlesex, one of the seven counties considered critical for success in the primary.

"I would think she would get overwhelming support (in the county)," said state Sen. Bob Smith, an influential Democrat from Middlesex.

Buono’s announcement was of little surprise. In recent weeks, she placed ads for a campaign manager, hired speech coaches and attended the Democratic Governors Association winter meeting in California.

She told supporters today that "grassroots donations and neighbor-to-neighbor organizing is going to be the foundation of our campaign for change."

Booker’s top political strategist, Mark Matzen, did not return phone calls today seeking comment.

Sweeney today said he plans to decide soon on whether to run for governor or U.S. Senate in 2014. "I have a lot of options," he said.

The Star-Ledger recently reported Sweeney has told at least three Democrats that he plans to run for governor if Booker refuses.

State Sen. Richard Codey (D-Essex) is also weighing a run, promising a decision before the end of the year. Asked about Buono’s announcement, he said: "Good luck. She’s a good Democrat."

Christie’s top political strategist Michael DuHaime was ready for the Buono announcement.

"I think Barbara represents all the failed tax and spend policies of the McGreevey and Corzine era," DuHaime said. "She has voted for $5.5 billion in tax and fee increases over the years."

Speaking to business leaders in Woodbridge today, Christie, who announced his re-election bid two weeks ago, didn’t mention any Democrat by name, but sounded very much like a candidate.

"Do we want to go back to the failed partisanship of today or do we want to work together to provide people with a hopeful and successful tomorrow?" he asked.

Buono has carved out space on the liberal side of the Democratic Party in Trenton, pushing for higher taxes on the wealthy, increases in the minimum wage and for the legalization of gay marriage. Before she was booted from the Senate Budget Committee for bucking party leadership, Buono also built a reputation as supporter of small businesses and boosting property tax relief.

Buono has worked hard at cultivating a relationship with Emily’s List, a national organization that helps progressive-minded women get elected which spent $51 million on candidates this year.

"It’s great to see so many women throw their hats in the ring for critical governor’s races," said Jess McIntosh, a spokeswoman for the group. "We look forward to continuing to talk to her."

Recent polls show Buono trailing Christie by as many as 40 points.

Star-Ledger staff writer Jenna Portnoy contributed to this report.

Related coverage:

• State Sen. Barbara Buono posts ad seeking campaign manager for gubernatorial run

• Cory Booker says Gov. Christie's bid for re-election has no bearing on decision to run

• Gov. Christie has strong support of N.J. voters, new poll shows

• Gov. Christie enjoys significant lead against potential Democratic opponents, poll says