TRENTON Sen. Stephen Sweeney emerged from a closed-door meeting Monday poised to become New Jersey's highest ranking Democrat in Trenton, marking what will be a major shift in legislative leadership when he is named Senate president in January.

The 3rd District legislator completed the political coup over Senate President Richard Codey following a lengthy caucus with fellow Senate Democrats.

"Our state is truly sitting at a crossroads," Sweeney said during a joint press conference with Assemblywoman Sheila Oliver, who will become the new Assembly Speaker come January. "The people said they want change in Trenton."

Sweeney, 50, of West Deptford Township, announced earlier this year he would challenge Codey for the top spot. Then, during a political power struggle, deals were struck to ensure Sweeney would have the votes to be successful on Monday.

"This was tough for him," Sweeney said of Codey. "He has done a great job. This wasn't anything against Sen. Codey. He has a career that everyone in this Legislature, Republican and Democrat, would die for."

Sweeney admitted to being "nervous" during a press conference to announce the leadership change.

"I have to be much more careful not to make too many mistakes," Sweeney said afterward. "Everything I say now has an enormous consequence. I have to choose my words much more carefully."

Legislators make an annual salary of $49,000; the leaders in each house make one-third more. As Senate president, Sweeney will be charged with setting the agenda. He will decide which bills go before the full Senate for a vote.

"Our state still faces a multi-billion dollar anticipated deficit," said Sweeney. "Closing it will require tough decisions and honest discussions about the scope of government and balancing what we want against what the people need."

For Codey, who spent 14 months as governor when then-Gov. James McGreevey abruptly resigned in November 2004, it has been a quick fall from power. After eight years at the Senate's helm, Codey was forced out when Sweeney announced last month that he "has the votes."

Scheduled to begin shortly after noon, Monday's Democratic caucus dragged late into the day.

At 1 p.m., Sweeney and Codey walked out together, but then parted ways without comment as they headed to the Senate Chambers to swear in a new colleague. An hour later, the caucus reconvened and continued to hash out next year's plan. The leadership change was announced nearly two hours later, following what was said to be a unanimous vote.

Sen. Barbara Buono, who chairs the Senate Budget and Appropriations Committee, nominated Sweeney to replace Codey. She will replace Sweeney as majority leader in January.

"We haven't always agreed on everything, but we have a great deal of respect for one another," Buono, D-Middlesex, said of Sweeney. "He is someone I know to be honest and independent."

As Codey emerged from the Democrat caucus room Monday afternoon, he said there was "a lot of blood on the floor."

Later, he congratulated the new Democrat leadership, which will officially change in January.

"It's been a great honor to serve as the leader of the Senate Democratic Majority for the past eight years," Codey, D-Essex, said in a statement. "This has, without question, been one of the greatest experiences of my life and I'm proud of the many progressive accomplishments we have made on behalf of the residents of New Jersey."

It remains unclear what Codey's role will be next year, but Sweeney assured it will be an "active" one.

Sweeney becomes the first Senate president from Gloucester County since 1952. He promised he will work closely with Gov.-elect Chris Christie, a Republican who defeated Gov. Jon Corzine in an election this month. The state Assembly and Senate will still have Democrat majorities in 2010.

"I hope to help our Governor-elect find some solutions to the fiscal insanity in our state," said Sweeney. "We will be fair. We will be open-minded. We may even agree more than we disagree."

Oliver will fill the post being vacated by Assembly Speaker Joseph Roberts, a South Jersey Democrat retiring after 22 years in the Legislature.

It all became clear that Codey was out and Sweeney was in as president when a deal was struck to have Oliver become the next speaker. With Oliver and Codey both from Essex County, it was unlikely the Legislature's two top spots would be held from elected officials from the same region.

"This is a time of great change for New Jersey and a time when we are faced with great challenges," said Oliver, who will become the first black woman named to lead the Assembly. "We will be fair and we will look for common ground."

Still unresolved in all of this is when Sweeney will step down as a Gloucester County freeholder. Sweeney, who serves as the all-Democrat board's director, previously said he will not seek re-election to the county position when his term expires in two years.

Now that he has been awarded this top leadership role in the Senate, Sweeney said Monday he will make a decision after he is sworn in to the new job on Jan. 12.

"I will figure out a proper way to transition myself out," said Sweeney.

Sweeney first joined the freeholder board in 1997 and was elected to the Senate four years later.

On Monday, Sweeney reminisced on his reasons for getting involved in politics. His daughter was diagnosed with Down syndrome, and Sweeney said he knew it was a necessary move.

"It opened my eyes to a world I didn't know existed," said Sweeney. "That was my motivation when I got into politics and it continues to be."