NEWARK — Bridget Anne Kelly, a former top aide to Governor Chris Christie, was sentenced to 18 months in prison on Wednesday for her role in closing access lanes to the George Washington Bridge as a form of political retribution against a mayor who refused to endorse Christie for reelection in 2013.

Earlier on Wednesday, Bill Baroni, 45, a former top official at the Port Authority of New York and New Jersey, was sentenced to two years in prison.

Kelly, 44, who was Christie’s deputy chief of staff, and Baroni, 45, had been found guilty by a federal jury last fall of conspiracy and fraud following a seven-week trial.

“What occurred in September of 2013 was an outrageous abuse of power,’’ Judge Susan D. Wigenton said as she handed down Baroni’s sentence in US District Court here, calling it a “sad day’’ for the state of New Jersey.

The sentencing of two high-ranking onetime aides and allies of Christie was another dramatic chapter in the court proceedings and investigations into the so-called Bridgegate scandal.

But the political damage to Christie, who saw his presidential ambitions dashed and national reputation tarnished, was both immediate and lasting.

The prosecutors portrayed Baroni’s actions as “brazen, calculated, and a mean-spirited use of power,’’ and repeatedly pointed to allegations of perjury during the trial as the basis for their recommendation of mandatory imprisonment.

“Those are the actions out of the playbook of some dictator of a banana republic,’’ said Lee M. Cortes, an assistant US attorney.

“It is incomprehensible that such actions could take place here, in the United States.’’

Initially defiant after he was charged and vowing to prove his innocence, in the courtroom on Wednesday Baroni was remorseful, as he and his legal team sought to avoid prison.

“That is why I regret, more than anything, that I allowed myself to get caught up in this and fail to help those who need it,’’ Baroni said, as he read from a prepared statement. “It was my job to protect them and I failed.’’

He added: “I let the people in Fort Lee down. They deserve someone in my position to have tried to stop this. But I didn’t stop this. No one else is responsible for my choice.’’

Kelly entered the courtroom before Baroni was sentenced. The two hugged, before Kelly made her way to her lawyers.

The scandal, which was designed to punish Mayor Mark Sokolich of Fort Lee for not supporting the governor’s reelection bid, created a massive traffic jam that ensnared emergency vehicles, school buses, and commuters in endless gridlock for five days on the streets near the bridge.

New York Times