NEWARK -- In the biggest New Jersey corruption scandal in recent memory, federal prosecutors began their case Monday describing the traffic chaos in Fort Lee when two former members of Gov. Chris Christie's inner circle allegedly shut down several toll lanes at the George Washington Bridge for four days in an act of retribution--and claimed the governor knew about it as it was going on.

"We're here today because not only was that conduct vindictive and mean spirited, it was criminal," assistant U.S. attorney Vikas Khanna told the jury.

He said that Bill Baroni, the former deputy executive director of the Port Authority of New York and New Jersey, and Bridget Anne Kelly, who served as Christie's deputy chief of staff, put their ambitions over their duties as stewards for the public.

"This case is about the defendants' abuse of power and their callous disregard for the people of Fort Lee," said Khanna.

Khanna, describing the chaos of the traffic jams that paralyzed Fort Lee beginning on Sept. 9, 2013, said David Wildstein, a former Port Authority employee who pled guilty to federal charges last year, will admit he was the one who came up with that idea.

The prosecutor added that Wildstein will testify he and Baroni told Christie about the scheme at the very moment traffic was at a standstill in Fort Lee during a Sept. 11 commemoration Manhattan.

"The evidence will show that Baroni and Wildstein were so committed to their plan to punish (Fort Lee) Mayor (Mark) Sokolich that during those precious few minutes that they had alone with the governor, they bragged about the fact that there were traffic problems in Fort Lee and that Mayor Sokolich was not getting his calls returned," the prosecutor said.

"He (Wildstein) will also tell you that Kelly instructed him to take that action and Baroni blessed it," he said.

The prosecutor did not suggest that Christie knew the reason for the traffic problem. The governor has repeatedly said he had no knowledge of it beforehand--a point reiterated by his office Monday.

Baroni and Kelly are on trial on nine counts of fraud and conspiracy in connection with the 2013 lane closures.

Defense attorneys, meanwhile, took direct aim at the government's star witness in the case, Wildstein, the former Port Authority appointee who orchestrated the lane shutdowns and has already pleaded guilty in the case, portraying him as an opportunist who was put into a powerful position for the sole purpose of fortifying the governor's then high-flying presidential aspirations.

"When David Wildstein spoke, Gov. Christie's voice came out and everybody knew it," declared defense attorney Michael Baldassare.

Calling Wildstein "a ventriloquist's doll sitting on the lap of Christopher J. Christie," he said the governor "knew full well who he was sending to the Port Authority" when the one-time political blogger was hired to a specially created $150,020-a-year position with no job description.

The defense also charged that Wildstein and the Christie administration used the Port Authority as a slush fund to ply New Jersey elected officials with millions in grants, jobs and sweetheart deals in exchange for their endorsements of the governor when he ran for re-election in 2013.

On trial in the case now playing out in federal court in Newark, Baroni and Kelly are charged with conspiracy and fraud in connection with the misuse of the resources of the Port Authority, which runs the George Washington Bridge, as well as violating the public's right to be allowed to travel freely.

Both maintain their innocence and say they will take the stand in their defense.

In their opening statements, prosecutors said Kelly and Baroni schemed to shut down local toll lanes at bridge as political retribution targeting Sokolich.

Khanna told jurors that Baroni and Kelly "worked hand in hand" to put pressure on a local elected official they hoped would endorse Christie's re-election bid. Sokolich was a coveted endorsement for Christie's re-election, but ultimately caught the ire of Kelly and Wildstein after it became clear the Democratic mayor wouldn't back the incumbent Republican.

"In 2013, Wildstein took political directions from Gov. Chris Christie's office ... and in doing so, he took directions from Bridget Kelly," Khanna said. "Wildstein had told her those lanes could be used at leverage against Mayor Sokolich."

It all came to a head less than a month after Kelly learned in August 2013 that Sokolich was not going to endorse the governor, and sent a text message to Wildstein, telling him "time for some traffic problems in Fort Lee."

Baldassare, who represents Baroni, drew sharp contrast between the narrative told by prosecutors and Wildstein, who he said was feared by those around him. Referring to the many profanities others used to describe him, the attorney told jurors "the government made a deal with the devil and they're stuck with him."

Wildstein was considered by others to be "a horrible person" who, for his "entire adult life, has had a double life," Baldassare said.

Despite public assertions from Christie arguing otherwise, Baldassare said Wildstein was put in place by the governor himself.

"The governor referred to David Wildstein as his fixer. He used to joke that Mr. Wildstein is his Mr. Wolf," referring to the Harvey Keitel character from the movie "Pulp Fiction" whose job was to come in and clean up the bodies.

At the same time, in a surprise revelation otherwise aimed at buttressing the honesty of Baroni--who is also accused of lying to the legislature when he testified that the bridge lane shutdowns were part of a legitimate traffic study--Baldassare told jurors that the former state senator had secretly cooperated with the FBI back in 2006 as an informant, at a time that agents were working on an investigation into lobbyists and legislators.

"They found again and again what Baroni told them was corroborated by evidence," said the attorney, who did not discuss the nature of the investigation.

Baldassare described Wildstein as a Republican political operative who played dirty tricks when he worked on campaigns in the past, including stealing the late U.S. Sen. Frank Lautenberg's jacket at an event "as a trophy," so that the aging former Democratic senator would would have to take someone else's coat and would be uncomfortable.

Wildstein also communicated with the governor when Christie was serving as U.S. Attorney, according to Baldassare, who claimed Christie frequently interacted with "Wally Edge," the pseudonym Wildstein used when he was an anonymous political blogger for PoliticsNJ, later PolitickerNJ.com. What's more, Baldassare charged that after Wildstein was pushed out of the Port Authority, he communicated with a "high ranking" lawmaker who served on the joint legislative committee that investigating the scandal.

Michael Critchley, who represents Kelly, took pains to show the single mother of four as a neophyte in the world of hardball politics, and that Wildstein was the one pulling the strings.

Kelly was thrown "under the presidential bus" when she took the fall and was charged, Critchley contended, adding she was not pulling the strings.

Instead, he called "the idea that Bridget Kelly is directing the affairs of the state of New Jersey" as "almost laughable," suggesting larger powers were at play when access lanes to the busiest bridge were closed on the eve of Christie's 2013 re-election.

"It's about a presidential campaign," Critchley said.

He asked jurors to remember back in 2013 when Christie, who just sailed to re-election, was widely acknowledged as the Republican Party's frontrunner in the 2016 presidential campaign.

Kelly shouldn't be elevated to "some grandiose position," Critchley said, noting she only held the deputy chief of staff title for three months.

Rather, Wildstein wanted to "shine in Chris Christie's eyes" as the governor readied for a nationwide campaign, Critchley argued.

"He wants to be on the national Chris Christie presidential team," he said.

"When Chris Christie was about to take over the world, he wanted everyone to know he was Chris Christie's Rottweiler," he remarked. "Now all of a sudden, when the focus is on David Wildstein for all the crimes he committed at the Port Authority, he transforms. He says he wasn't a Rottweiler; he was a Shih Tzu."

The case continues Tuesday morning before U.S. District Judge Susan Wigenton, when Fort Lee Police Chief Keith Bendul, Sokolich and Port Authority Executive Director Patrick Foye are expected to testify.

Ted Sherman may be reached at tsherman@njadvancemedia.com. Matt Arco may be reached at marco@njadvancemedia.com. Follow him on Twitter @MatthewArco or on Facebook. Follow NJ.com Politics on Facebook.