Now that a federal judge has voided Paul Manafort's plea deal with the special counsel Robert Mueller, Manafort's best shot at avoiding spending the rest of his life in prison hinges on being pardoned by President Donald Trump.

But it may not be that straightforward: with the 2020 election around the corner and a newly empowered Democratic-led House of Representatives, pardoning Manafort is a politically risky move for the president.

Even if Manafort's gamble pays off and he secures a pardon, he's still not out of the woods. In that case, said one Justice Department veteran, "the stopwatch starts on various state prosecutors in New York, Virginia, Washington, DC, and anyone else who might have the jurisdiction."

It's unclear why Manafort made such a risky gamble.

"He is simply a con man and grifter who seems to be in constant motion to avoid doing the right thing and telling the truth," said the former federal prosecutor. "He is always looking for the angle and will do so until the cell door locks behind him."

But one criminal defense attorney, who requested anonymity because they are actively involved in the Mueller probe, floated another option: "Maybe Manafort was lying because telling the truth would reveal something more sinister," they told INSIDER.

Paul Manafort's chances of skirting a lifelong prison term could now hinge on the personal whims of a man who has shown little loyalty to those around him.

That was the general consensus among legal scholars after a federal judge ruled this week that Manafort, the former chairman of President Donald Trump's campaign, violated his plea deal with the special counsel Robert Mueller by lying to prosecutors about several threads in the Russia investigation.

US District Judge Amy Berman Jackson nullified Manafort's plea deal as a result and released Mueller from any obligations he had to show Manafort leniency.

"Most prosecutors have seen defendants about to be sentenced who truly regret their actions and are determined to start a new lease on life once they serve their sentence," Jeffrey Cramer, a longtime former federal prosecutor who spent 12 years at the Justice Department, told INSIDER. "We have also seen individuals who are anti-social and simply do not care if their actions hurt others either physically or financially."

But Manafort, he said, "fits into a third category. He is simply a con man and grifter who seems to be in constant motion to avoid doing the right thing and telling the truth. He is always looking for the angle and will do so until the cell door locks behind him."

One criminal defense attorney, who requested anonymity because they are actively involved in the Mueller probe, floated another option: "Maybe Manafort was lying because telling the truth would reveal something more sinister," they told INSIDER. "Who else would risk doing something this stupid without a guarantee of freedom?"

Read more: A judge nullified Paul Manafort's plea deal with Mueller after ruling that he lied to prosecutors

Robert Mueller. REUTERS/Kevin Lamarque

'Like a guy shooting craps down to his last chip, Manafort has placed himself in an unenviable position'

Jackson ruled Wednesday that Manafort made false statements to prosecutors about:

A $125,000 payment made to a firm in 2017 related to a debt that Manafort had incurred.

His interactions with the former Russian intelligence operative Konstantin Kilimnik and Kilimnik's role in the alleged conspiracy to obstruct justice by trying to influence the testimony of two witnesses in February.

Information that was pertinent to another Justice Department investigation.

Manafort has been charged twice in the Mueller probe for offenses relating to his years of work lobbying for a pro-Russian Ukrainian political party in the US. Following his first trial, he was convicted on eight counts of tax and bank fraud.

Manafort was scheduled to go to trial again in September, but instead struck a deal with the special counsel's office to plead guilty to one count of conspiracy and one count of obstruction of justice in exchange for his cooperation.

Now that his plea deal has fallen apart, Justice Department veterans say Manafort's freedom depends on Trump.

"Manafort will spend the rest of his life in prison (unless pardoned)," wrote Elie Honig, a former federal prosecutor from the Southern District of New York who prosecuted hundreds of organized-crime cases.

Cramer echoed that view.

"Like a guy shooting craps down to his last chip, Manafort has placed himself in an unenviable position," he said. "Manafort never thought Mueller would learn about his post-cooperation duplicity. Now, he must wait for a presidential pardon from a many who hasn't demonstrated much loyalty to those around him. That's a gamble on a level that's hard to imagine."

Read more: Former Trump lawyer John Dowd predicts Mueller's report will never see the light of day

President Donald Trump listens to a question during a cabinet meeting at the White House, Tuesday, Feb. 12, 2019, in Washington. (AP Photo/ Evan Vucci) Associated Press

Even if Manafort gets a pardon, 'the stopwatch starts on various state prosecutors'

Trump and his allies have embarked on a months-long public relations campaign aimed at discrediting the Russia probe and Mueller, whom they accuse of going on a politically motivated "witch hunt" against the president and his associates.

Though Trump initially backed his former campaign advisers and administration officials against prosecutors, the White House later distanced itself from them as the special counsel secured more indictments and guilty pleas.

When it surfaced that the former Trump campaign foreign policy aide George Papadopoulos had admitted to lying to the FBI and was cooperating with prosecutors, the White House dismissed him as a low-level "coffee boy."

When the FBI raided the property of Trump's former lawyer and longtime fixer, Michael Cohen, the president came out swinging in his defense. But as time went on, the White House cut Cohen off, and when Cohen began cooperating with prosecutors, Trump and his lawyer, Rudy Giuliani, began publicly bashing Cohen. Cohen also recently alleged that they had made threats against him and his family.

Manafort and the former US national security adviser, Michael Flynn, are the only two people in Trump's inner circle embroiled in the Russia probe who have not been public targets of his anger. Last year, The New York Times reported that Trump's former defense lawyer, John Dowd, floated pardons to both men in the summer of 2017 in what appeared to be a quid pro quo offer in exchange for their silence.

Former Mayor of New York Rudolph Giuliani during the Conference In Support Of Freedom and Democracy In Iran on June 30, 2018 in Paris, France. The speakers declared their support for the Iranian peoples uprising and the democratic alternative, the National Council of Resistance of Iran and called on the international community to adopt a firm policy against the mullahs regime and stand by the arisen people of Iran. (Photo by Anthony Devlin/Getty Images)

Trump has publicly defended Manafort in recent months, praising his refusal to "break."

Giuliani also told INSIDER last year that even though Manafort had struck a cooperation deal with prosecutors, his joint defense agreement with Trump was still in effect. At the time, legal scholars brushed off Giuliani's claim, saying it would be impossible for Manafort to cooperate against the president while remaining in a joint defense agreement with him.

But several weeks later, it surfaced that Mueller's team was furious because it had learned that Manafort's lawyers were briefing Trump's team on what their client was being questioned about in connection with the investigation.

Those events, Justice Department veterans told INSIDER, don't point to a coherent legal strategy, but to a play for a presidential pardon.

It may not be that simple, however.

With the 2020 presidential election around the corner and a newly empowered Democratic-led House of Representatives, "Trump knows that a Manafort pardon is politically risky right now and will only hasten talk of impeachment," Jens David Ohlin, a vice dean at Cornell Law School who is an expert in criminal law, told INSIDER.

"Ironically, Manafort's best hope is that Trump loses the 2020 election and then pardons Manafort on his way out of the White House," he added.

Even then, Manafort may not be out of the woods.

Manafort has been accused of laundering millions of dollars, failing to pay income taxes, and actively engaging in assisting outside governments that are often hostile to the US without registering as a foreign agent.

If his gamble pays off and Trump grants him a pardon, "the stopwatch starts on various state prosecutors in New York, Virginia, Washington, DC, and anyone else who might have the jurisdiction," Cramer said.