In Perth Amboy, it was Wisniewski's political muscle being tested in what those involved and political observers called a proxy fight. "It became the battleground for control of the county by Democrats," recalled the challenger, Billy Delgado. "People that had never set foot in Perth Amboy suddenly were there campaigning."
The candidates spent more than $400,000 on the election, and the incumbent, Mayor Wilda Diaz, won. Wisniewski took a hit.
The loss was "seen as sealing his status as outside the power structure," said Patrick Murray, a political analyst at Monmouth University.
Wisniewski says he did not consider the election a tough loss. "In the political arena, you have to be prepared to make choices and defend your choices," he said. "If anybody gets into this and thinks their choices will always be universally correct, that's just not the way life goes."
Wisniewski, 51, who held the unenviable job as state Democratic Party chair during Gov. Christie's rise and who has been unsuccessful attaining a top legislative position, now leads an investigation that has grabbed national attention and could make or break careers.
Democratic leader at 17
The son of a millwright at the National Lead Factory and a secretary, Wisniewski (pronounced wis-NESS-key) grew up in Sayreville, Middlesex County.
His father, Felix, was chair of the municipal Democratic Party and a borough councilman, and Wisniewski became president of the Sayreville Young Dems at age 17.
Long before the world had heard "Livin' on a Prayer," Wisniewski sat in the same high school science class as Jon Bon Jovi. "He was clearly a gifted, accomplished musician," Wisniewski said last week in his Statehouse office. "I don't think anybody doubted that. Who would have thought he's going to be a world-famous rock star?"
(They ran into each other in fall 2012 at a fund-raiser for President Obama.)
Wisniewski later graduated in the same law school class at Seton Hall as Chris Christie and now has his own law firm in Sayreville. He does not recall knowing the future Republican governor well, if at all, in college.
First elected to the Assembly in 1995, Wisniewski has been on the front lines of transportation issues dating to the installation of E-ZPass.
Along the way, the father of three has helped pass legislation aimed at improving safety for young drivers - including a law requiring drivers under 21 to display decals on their license plates - and also worked to get fire sprinklers installed in all college dormitories.
Wisniewski has bucked his own party leadership, opposing Gov. Jon S. Corzine's unsuccessful plan to privatize the state's highways and more recently voicing opposition to Sweeney's attempt to abolish the Rutgers board of trustees.
At 6-foot-5, Wisniewski is usually the tallest person in the room at the Statehouse. He is described as statesmanlike and polite, even as political foes accuse him of running a partisan witch-hunt. "I understand your suspicion, your skepticism, and that's your role. I compliment you on that," he replied to one such Republican criticism last week.
Yet one Democrat said Wisniewski's bare ambition (he sought to become speaker in 2009 and contemplated a run for governor last year) and formal, old-school approach to legislating ("very congressional") had turned off some in his party.
Wisniewski is "kind of an island" in Middlesex County politics, said the Democrat, who asked not to be named in order to offer a candid assessment. "He doesn't have allies."
"Being accused of having ambition is an occupational hazard if you hold office," Wisniewski said. "I'm very comfortable in all the things I've done and pursued."
The Democrat called Wisniewski a smart lawyer. As party chair, Wisniewski helped secure legislative redistricting favorable to Democrats - which the GOP blames for failing to pick up any seats in the November elections.
The roots of Bridgegate
Before Bridgegate became part of the national political lexicon, Wisniewski was plugging away with an inquiry into the operations and finances of the Port Authority of New York and New Jersey after the agency raised tolls and was criticized in a January 2012 audit as dysfunctional and lacking proper oversight.
"It wasn't the sexiest issue," said Senate Majority Leader Loretta Weinberg (D., Bergen).
Weinberg raised concerns about bizarre traffic jams on the George Washington Bridge in September, and Wisniewski, whose Transportation Committee already had subpoena power, offered to take up the cause.
Weinberg said Wisniewski told her: "Respectfully, I don't want to step on your toes."
"I encouraged him to feel free to please step," said Weinberg, who last week became his co-chair on a joint investigatory committee.
In the fall, the Assembly Transportation Committee began to probe closures of access lanes from Fort Lee to the bridge that were carried out without consulting local officials.
A paper trail and testimony - including the now-infamous e-mail "Time for some traffic problems in Fort Lee" - led the panel to the Governor's Office in late December 2013.
Christie fired the e-mail's author, deputy chief of staff Bridget Kelly, and cut ties with Bill Stepien, a former campaign manager who also was implicated in a trove of subpoenaed documents. Two other allies have resigned.
The correspondence suggests the closures were politically motivated.
Christie has said he had no knowledge of his staff's role in the scheme and has not been accused of wrongdoing by legislators and authorities. On Friday, an attorney for David Wildstein, one of the governor's appointees at the Port Authority, accused Christie of having knowledge of the lane closures. Christie's office again denied that claim Friday.
Though lawmakers in Trenton agree the disclosures warrant further investigation, Republicans have taken issue with Wisniewski's approach.
"I respect him. He's a good lawyer. But no one's going to mistake him for a nonpartisan," said Assemblyman Michael Patrick Carroll (R., Morris), who had urged giving the Legislature's special investigatory committee equal political representation. It consists of eight Democrats and four Republicans.
Carroll noted that Wisniewski had used the word impeachment on a television news program several weeks before, fueling suspicions that the investigation was taking a partisan turn. Wisniewski had been asked about possible consequences if Christie were implicated.
Wisniewski acknowledges the mistake. "Clearly, that the spotlight has been put on the issue reminds me that I have to be very careful about what I say and how I say it," he said.
"Obviously, there's a lot of people looking at this and they're trying to read the tea leaves about future elections for the governor and political positions," he said. "That's not my thing. I'm not looking at it for that."