TRENTON, New Jersey (Reuters) - Former top aides to New Jersey Governor Chris Christie have not cooperated with a state probe into a traffic scandal that threatens the Republican governor's political future out of fear they will incriminate themselves, their attorneys argued in court on Tuesday.
Bridget Kelly, Christie's former deputy chief of staff, and Bill Stepian, his former campaign manager, have refused to turn over records and documents sought by state lawmakers looking into the September incident, when Christie aides apparently helped orchestrate traffic jams at the busy George Washington Bridge.
The closing of several access lanes to the bridge, ostensibly for a traffic study that never materialized, caused extensive delays for four days in the town of Fort Lee, whose Democratic mayor had not endorsed Christie's re-election bid.
Christie, widely seen as a potential Republican candidate for the White House in 2016, has said he was unaware of his aides' actions and has severed ties with several of them.
Nevertheless, the scandal has hurt his image and polls, including two new surveys released on Tuesday, show him losing ground as a potential presidential contender.
A Fairleigh Dickinson University survey showed Christie's job approval rating tumbling 20 points, with 41 percent of registered state voters approving of his job performance, compared with 61 percent after his re-election in November.
His disapproval rating stands at 44 percent, the first time it has ticked higher than his approval rating, the poll said.
A Rutgers-Eagleton poll found Christie's "trustworthiness" at an all-time low of 23 percent among registered voters, down 20 points from October.
Subpoenas were issued to Kelley and Stepian in January by members of the Democrat-controlled state legislature, and Mercer County Superior Court Judge Mary Jacobson had ordered them to court to explain why she should not force them to comply.
After listening to the arguments, the judge said she would issue a ruling possibly at the end of the month.
Stepian's attorney argued that producing documents in the case could compel his client to provide evidence against himself and that the U.S. Constitution provides protection against self-incrimination.
"The Fifth Amendment says quite specifically that you can't be forced to be a witness against yourself," said the attorney, Kevin Marino.
Stepian did not attend the hearing, but Kelly was there, at times looking distraught. Neither one was required to attend.
Kelly's attorney Michael Critchley said she attended the proceedings to show she has not been hiding away. Kelly has avoided the public eye since the scandal broke in early January.
"She's here because her life has been affected dramatically," Critchley said.
Although the judge made no ruling, she laid out a timetable ordering attorneys for the state lawmakers investigating the case to submit additional documents by March 17 and attorneys for Kelly and Stepian to do so by March 24. She said she would make a decision as soon as possible after then.
During the hearing, which lasted nearly four hours, attorneys sparred over an array of issues such as whether the legislative panel can grant immunity from prosecution, whether some of the most damaging documents released to the public were authentic and whether the subpoenas issued to Kelly and Stepian were specific enough or merely efforts to fish for information.
"This is not, has not been and the subpoenas are not fishing expeditions of any sort," said Reid Schar, an attorney for the state lawmakers' panel.
The scandal exploded with the public release of emails in January that included one by Kelly to Port Authority executive David Wildstein saying: "Time for some traffic problems in Fort Lee."
Wildstein, a Christie appointee, replied: "Got it."
Wildstein resigned late last year, and Christie fired Kelly in January.
While the attorneys for Kelly and Stepian cited their clients' rights against self-incrimination, the issue arose in the hearing that some government officials in effect waive that legal protection because documents they produce could be considered public.
Kelly's attorney suggested the legislative panel give her immunity from prosecution, but the panel's attorney said it did not have the authority to do so.
The judge noted that the panel could not provide such broad blanket immunity that would afford protection from a federal investigation.
The U.S. Attorney for New Jersey, Paul Fishman, has opened a separate federal investigation into the traffic jams, which slowed school buses and emergency vehicles on the bridge that spans the Hudson River between New Jersey and New York.
Subpoenas were issued as well to other top Christie aides and his appointees at the Port Authority of New York and New Jersey, which oversees the bridge.
Outside the courthouse, Stepian's attorney said his client had done nothing wrong.
"It would be a terrible injustice for anyone to be prosecuted in this case," Marino said.
Writing by Ellen Wulfhorst; Editing by Scott Malone, Jonathan Oatis and Gunna Dickson