President Donald Trump and his allies are worried his longtime personal lawyer Michael Cohen, who is under federal criminal investigation, will flip.

Experts say their concerns likely have merit, but are torn over whether Cohen will actually turn on the president.

While some say the chances of flipping are good if Cohen faces a potentially long jail term if convicted, others say his continued loyalty to the president could work out for him in the end.

President Donald Trump and his loyalists are worried.

Trump, who is already facing tremendous pressure from the special counsel Robert Mueller's Russia investigation, was thrust into another legal controversy last week when it emerged that the FBI is investigating his personal lawyer, Michael Cohen, for possible financial crimes and campaign finance violations.

Armed with a search warrant, investigators working for the Manhattan US attorney's office raided Cohen's office and hotel room to seize: tape recordings, financial records, documents pertaining to payments made to women who have alleged affairs with Trump, material relating to a 2005 "Access Hollywood" tape featuring Trump saying lewd things about women, electronic devices, and communications between Trump and Cohen.

The warrant specifically authorized FBI agents to seize the materials, and it also mentioned Trump by name several times.

Now, it looks like Trump and his advisers are not only concerned about the gravity of the situation, but that Cohen will do what several other defendants in the Russia investigation have done: turn on the president.

'You can never say somebody will not flip'

Cohen has been referred to at different times as Trump's fixer, pit bull, and consigliere. His relationship with Trump stretches back decades, and he worked at the Trump Organization for over 10 years, beginning in 2006. Cohen left the company in 2017 to serve as Trump's personal lawyer.

"Anyone that takes care of problems and buries the bodies is not someone you want to testify against you," said Jeffrey Cramer, a former federal prosecutor who spent 12 years at the Justice Department. "The damage Cohen can do is far greater than everybody else combined."

Anyone that takes care of problems and buries the bodies is not someone you want to testify against you.

Vanity Fair reported last week that Cohen has been dismayed by the lack of support from Trump's inner circle since the raids. And two sources close to Trump told Politico that people in the president's orbit have been actively discussing the possibility of Cohen flipping as his legal troubles mount.

Meanwhile, Trump's longtime legal adviser, Jay Goldberg, reportedly warned the president in a phone call last week that on a scale of one to 100, where 100 is fully protecting the president, Cohen "isn't even a 1."

"If there's one thing you learn from working with cooperators and people who flip in federal investigations, it's that you can never say somebody will not flip," said Alex Whiting, a longtime former federal prosecutor who practiced in Boston and Washington, DC. "People you would never imagine would flip because of their loyalty or personal relationship with someone, when faced with the prospect of a long prison sentence, will often flip."

Jack Sharman, a white-collar defense lawyer who served as a congressional special counsel during the Whitewater investigation, said the prospect of Cohen flipping poses a significant risk to Trump.

"Lawyers know secrets, and appropriately so," Sharman said. "Confidentiality is the foundation of attorney-client privilege. Because a lawyer tends to know a great deal about the client even in areas that do not relate directly" to a the focus of a criminal investigation, "a cooperating lawyer can pose risks that are difficult for the defense to anticipate and deal with."

If Cohen agreed to cooperate, it would be part of what's known as a global resolution. That means Cohen would not only be cooperating with the Manhattan US attorney's office but with any other federal criminal inquiries, like the Russia probe, that he may have information prosecutors want to know.

Cohen's alleged crimes

Stormy Daniels, accompanied by her attorney Michael Avenatti, talks to the media as she leaves Cohen's hearing in federal court on April 16, 2018 in New York. Mary Altaffer/AP Cohen is currently being investigated by the US attorney's office for the Southern District of New York for possible bank fraud, wire fraud, and violations of election law.

Earlier this year, Cohen admitted to paying $130,000 to Stormy Daniels, a porn star and director who says she had an affair with Trump in the mid-2000s, shortly before the 2016 US election.

If Cohen made the payment to boost Trump's chances of winning the election, and if Trump or his campaign knew about it, election law experts said it could be seen as an in-kind political contribution. The federal limit for individuals making donations of that type is $2,700.

Cohen said he made the payment himself by borrowing against his home equity loan. Federal investigators are looking into whether Cohen misled any banks in order to get the money by claiming it was for another purpose.

The FBI also seized records from Cohen's office connected to a separate $150,000 payment that the parent company of The National Enquirer made to a former Playboy model who also claims to have had an affair with Trump. The chief executive of the company is a close friend of the president.

It also emerged last week that Cohen negotiated a $1.6 million payment in late 2017 on behalf of former Republican National Committee fundraiser Elliott Broidy, another close Trump associate, to a former Playboy model who said Broidy impregnated her.

'He happened to land the big one with Donald Trump and got in a lot of trouble'

President Donald Trump has expressed full confidence in Cohen, railing against the FBI raids. Lynne Sladky/AP

Stressing that it's difficult to know more about the possible consequences without the full details of Cohen's activities on behalf of Trump and his loyalists, Whiting said there is a "potential here for serious jail time, and that certainly increases his chances of cooperation."

Cramer offered a differing view, saying he believed the chances of Cohen flipping are far lower than that of others who have flipped against Trump so far.

If Cohen decides not to cooperate with investigators and is convicted following a criminal investigation, he has a higher chance of receiving a pardon than other Trump associates because of the nature of his relationship with the president.

And if Cohen isn't pardoned, he will likely face a shorter jail sentence than other defendants, like former Trump campaign chairman Paul Manafort, who is accused of laundering tens of millions of dollars and faces up to 20 years in prison if convicted.

He's a small-time fixer whose small-time client happened to become president.

Cohen, Cramer said, hasn't been accused of that level of financial misconduct: "He's a small-time fixer whose small-time client happened to become president."

If Cohen were to be convicted and served a shorter jail term, "he comes out the other end of this a disbarred lawyer who still has the loyalty, trust, and appreciation of the President of the United States," Cramer said. "And he could easily be looking at a career as a top executive at the Trump Organization."

On the other hand, if Cohen agreed to testify against Trump, a possible pardon or commutation would be off the table.

In that scenario, Cohen would be "a disbarred lawyer who lost his biggest client," Cramer said.

"He happened to land the big one with Donald Trump and got in a lot of trouble," Cramer added. "And Cohen, in classic New York lawyer fashion, rolled up his sleeves and took care of it. That's a loyal person."