The U.S. Supreme Court on Thursday reversed the convictions of two onetime allies of former New Jersey Gov. Chris Christie, ruling in a unanimous decision that they did not violate federal fraud laws in the political scandal known as “Bridgegate.”

Bridget Anne Kelly, Christie’s former deputy chief of staff, and Bill Baroni, Christie’s top executive appointee at the Port Authority of New York and New Jersey, were convicted in 2016. Each faced prison time, and Baroni ended up serving about three months at the Loretto Federal Correctional Institution in Pennsylvania.

Their convictions stemmed from a 2013 political payback scheme in which prosecutors alleged Kelly, Baroni, and others caused massive traffic jams near the George Washington Bridge in order to exact retribution against a New Jersey mayor for his refusal to endorse Christie’s reelection campaign. The scandal hobbled Christie, a Republican, in the 2016 presidential campaign, a race in which he had been seen as an early front-runner before the rise of Donald Trump.

“The evidence the jury heard no doubt shows wrongdoing — deception, corruption, abuse of power,” Justice Elena Kagan wrote for the court. “But the federal fraud statutes at issue do not criminalize all such conduct.”

The court’s 9-0 decision marked its latest blow to public corruption prosecutions. Most notably, the high court in 2016 narrowed the scope of federal bribery statutes when it overturned the conviction of former Virginia Gov. Bob McDonnell. With the ruling, Bridgegate became the U.S. Justice Department’s second major public corruption case to fall flat in less than three years, following the 2017 mistrial and subsequent dismissal of a bribery prosecution against U.S. Sen. Bob Menendez (D., N.J.).

Christie on Thursday called the decision a “complete exoneration for my team from the prosecutorial misconduct” of then-U.S. Attorney Paul Fishman “and the Obama Justice Department.”

Christie, a former U.S. attorney in New Jersey appointed by President George W. Bush, accused Fishman, an appointee of President Barack Obama, of being motivated by “political partisanship and blind ambition,” costing taxpayers “millions in legal fees” and changing “the course of history.”

In his successful 2009 campaign for governor, Christie ran on a record of convicting dozens of politicians on corruption charges.

Fishman — who also successfully prosecuted Port Authority chairman David Samson, a Christie appointee and friend, on extortion charges — said it was “stunning, but perhaps not surprising, that Chris Christie’s response is to concoct accusations of political ambition, partisanship, and personal vindictiveness.”

He added that the court’s ruling did not “negate the work of the career prosecutors and law enforcement agents who uncovered and exposed those responsible” for the bridge scheme, “their motivation to assist Chris Christie’s reelection, and the many lies they told to cover their tracks.”

Mark E. Coyne, an appellate lawyer in the U.S. Attorney’s Office in Newark, said the Supreme Court’s decision “speaks for itself” and that the office had no additional comment.

Trump weighed in on Twitter, congratulating Christie and calling the prosecution a “grave misconduct by the Obama Justice Department!”

As a Christie opponent in 2015, Trump said Christie “totally knew about” the scheme. Christie has maintained that he had no knowledge of the revenge plot.

Gov. Phil Murphy, a Democrat and Christie’s successor, called the scandal a “stain” on the state. “There’s no escaping that this was a deep violation of public trust,” he said during a news briefing Thursday.

Prosecutors alleged at trial that Kelly and Baroni conspired to reduce the number of bridge access lanes available to commuters in Fort Lee from three to one, resulting in four days of gridlock in the town and endangering public safety.

Kelly and Baroni worked with another Christie ally — former Port Authority official David Wildstein — to cover up the scheme by saying the lane realignment was part of a “traffic study,” prosecutors said. Wildstein pleaded guilty to conspiring with Kelly and Baroni and then testified against them at trial. He received probation.

The crux of the prosecution’s case was that Kelly and Baroni committed property fraud by misusing public resources at the federally-funded Port Authority. By lying about a fake traffic study, they were able to trick career employees into executing the lane reductions, prosecutors alleged.

» READ MORE: Bridgegate got its day at the Supreme Court and the justices seemed skeptical that crimes were committed

It was that lie that triggered the federal fraud statute, attorneys for the government told the justices during oral arguments in January, because it showed the defendants would not have otherwise been able to execute the plot. The lane reduction also cost the Port Authority money by diverting resources and staff, the government said.

But the high court found that the realignment was “an exercise of regulatory power — something this court has already held fails to meet the statutes’ property requirement.”

“Because the scheme here did not aim to obtain money or property, Baroni and Kelly could not have violated the federal-program fraud or wire fraud laws," Kagan wrote.

Contrary to the government’s assertion, Kelly and Baroni “did not ‘commandeer’ the bridge’s access lanes,” Kagan wrote. "They (of course) did not walk away with the lanes; nor did they take the lanes from the government by converting them to a non-public use. Rather, Baroni and Kelly regulated use of the lanes, as officials responsible for roadways so often do — allocating lanes as between different groups of drivers.”

The Port Authority employees’ labor "was just the incidental cost of that regulation, rather than itself an object of the officials’ scheme,” Kagan added.

Michael Critchley, an attorney for Kelly, said he was “thrilled that Bridget can finally put this nightmare behind her and hopefully enjoy some sense of peace.”

“From the very beginning, we argued that this case was an indictment in search of a crime and vowed to continue fighting until the unjust verdict was overturned,” Critchley said in a statement. “The Supreme Court’s decision today confirms that we were right all along and that Bridget Kelly never committed any crime.”

The scandal erupted in January 2014, just months after Christie won a landslide reelection, when emails surfaced linking the bridge plot to the governor’s office.

“Time for some traffic problems in Fort Lee,” Kelly wrote in an August 2013 email to Wildstein. “Got it,” he replied.

At the time, Christie declared himself “embarrassed and humiliated by the conduct of some of the people on my team."

Evidence at trial showed Baroni, Kelly and Wildstein began the lane reductions on the first day of school to maximize punishment of Fort Lee Mayor Mark Sokolich. They didn’t alert local officials ahead of time, and refused to answer the mayor’s calls while the town was in gridlock.

Kelly and Baroni testified they believed the traffic study was legitimate.

Wildstein testified that Christie laughed when Baroni told the governor during a 9/11 commemorative event in Manhattan on Sept. 11, 2013, about the havoc underway at the bridge.

Kelly and Baroni were indicted in 2015 on charges including conspiracy, fraud, and violating Fort Lee residents’ civil rights.

They were convicted on all counts in November 2016. Two years later, a federal appeals panel in Philadelphia affirmed most of the convictions.

A federal judge sentenced Kelly to 13 months in prison. Baroni was sentenced to 18 months in prison and had already served about three months of his term when the Supreme Court said last year it would hear the defendants’ appeal. He was released shortly thereafter pending the appeal.

“Today is a long-awaited victory,” Baroni said in a statement. “But, as we are all living in the time of coronavirus, my joy in being vindicated is tempered by my concern for the people with whom I served time in prison. This is a scary time for all of us; it is especially scary for people in prison who can’t self-isolate; can’t socially distance; can’t stay six feet apart. I am going to do all that I can to make sure they are not forgotten.”

Staff writer Pranshu Verma contributed to this article.