New Jersey Gov. Chris Christie took responsibility again Tuesday for the scandal over politically motivated traffic jams, as he sought to use his State of the State Address to refocus attention on his policy goals for a second term.

As he acknowledged "mistakes were clearly made," Christie vowed to "cooperate with all appropriate inquiries to ensure this breach of trust does not happen again."

The Republican's reference to the revenge-motivated lane closures on the busy George Washington Bridge and the controversy that threatens his political future opened a speech outlining his plans for education, property tax relief and other priorities.

"The last week has certainly tested this administration," Christie said. "Mistakes were clearly made. And as a result, we let down the people we are entrusted to serve. I know our citizens deserve better — much better."

Christie said he wanted to assure New Jersey residents that the scandal known as Bridgegate "does not define us or our state" nor will it get in the way of progress. "I am the leader of this state and its people and I stand here today proud to be both," he said, as he promised to "do better."

Christie has been out of sight since last Thursday, when he apologized repeatedly for his administration's role in the traffic jams last fall. He also fired a top aide and cut ties to a political ally, then visited the Democratic mayor of Fort Lee to express his regrets in person.

The governor's State of the State Address — normally a chance to outline a new agenda and brag about accomplishments of the past year — was Christie's first opportunity to change the current conversation that he's a vindictive political bully.

Still to come: Christie's inaugural address on Jan. 21 when the Republican is sworn in for a second term and his presentation Feb. 25 of a new budget to the Democratic-controlled Legislature. Can the governor stop the steady drip of scandal-tinged headlines?

"The larger political problem for Christie is one of escalation," says Benjamin Dworkin, director of the Rebovich Institute of New Jersey Politics at Rider University. "He's gone from being called a bully, which most voters didn't seem to mind, to accusations of abuse of power, which may have a much more lasting negative impact.

"So while Christie used to be seen as the schoolyard thug, a big kid picking on smaller kids, now he's portrayed as a vicious teacher, singling out a child for torment," Dworkin says. "It's not just bullying. It's abuse of power, and it is a whole new narrative that he has to combat."

Christie's speech included new education policy proposals, an area the governor focused on in his first term. Having already battled teacher's unions over tenure rules and merit pay, Christie proposed a longer school day and school year.

He also called on New Jersey residents to create "an attitude of choice" as they work together to build on his first-term achievements. Christie touted his record of pushing through four balanced budgets, an overhaul of the state's pension rules and a cap on property taxes.

"It's not about choosing everything; it is not about saying yes to everyone," Christie said. "It is about setting our priorities and choosing to invest in New Jersey where it matters and to put in place the reforms and reductions that make it possible."

Since Christie's nearly two-hour news conference last week, investigations into his administration have widened:

• The state Assembly will convene a special panel with subpoena power to investigate the lane closures, which tied up traffic for days on the Fort Lee end of the bridge. More than 2,000 pages of documents suggesting politics was behind the traffic jams were released. These documents also show that Christie's top aides tried to thwart reporters who inquired about the lane closures.

• Ads promoting tourism in New Jersey in the wake of Superstorm Sandy, featuring Christie and his family, are the subject of a separate investigation by the U.S. Housing and Urban Development Department. The ads, paid for with disaster funds, appeared on TV in the run-up to the November election, when Christie easily won a new term.

• Christie's standing in New Jersey has taken a hit since copies of e-mails between Christie aides and appointees became public last week. About half of New Jersey's adults think Christie knew his staff was involved in the scandal known as Bridgegate, according to a Monmouth University/Asbury Park Press poll released Monday. And 51% say they don't think Christie has been "completely honest" about what he knows about the lane closures, the poll found.