President Donald Trump's approach to an ongoing impeachment inquiry and the whistleblower complaint that launched it bear several striking parallels to how the mafia operates.

Among other things, Trump accused the whistleblower of espionage, said the congressman investigating him should be tried for treason, accused lawmakers of attempting a coup, slammed witnesses who testify against him as rats, and said prosecutors probing him are corrupt.

A former federal prosecutor who was part of the team that convicted the Gambino crime family boss John Gotti told Insider: Gotti's "lawyers accused the prosecutors and the FBI of wrongdoing. They attacked witnesses. They attacked us."

"They got protesters to march in front of the courthouse. They went on TV and smeared us with ad hominem attacks," he added. "They planted stories in the press. They did everything Trump is doing, but he's doing it on a much larger scale."

Federal prosecutors who investigated Trump's campaign for conspiring with Russia during the 2016 race also treated the case like they would an organized-crime syndicate.

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The whistleblower who filed a complaint against him committed espionage. The congressman investigating him should be tried for treason. The lawmakers weighing whether to impeach him are attempting a coup. The witnesses who testify against him are rats. The prosecutors probing him are corrupt.

That's a sample of the attacks President Donald Trump has lobbed at his perceived enemies as he faces an ongoing impeachment inquiry amid allegations that he used his public office for private gain.

The latest volleys came on Tuesday. Early in the morning, the president praised the State Department's decision to block US ambassador to the EU Gordon Sondland from testifying voluntarily before Congress as part of the impeachment probe.

Trump said that while he'd "love to send" Sondland to testify, "he would be testifying before a totally compromised kangaroo court, where Republican's [sic] rights have been taken away, and true facts are not allowed out for the public ... to see."

Later in the day, Trump's White House counsel, Pat Cipollone, told House Democrats in a letter that the president and his administration would not cooperate with the "partisan and unconstitutional" impeachment inquiry.

Patrick Cotter, a former federal prosecutor who was on the team that convicted the Gambino crime family boss John Gotti, said he's struck by the parallels between Trumpworld's handling of the impeachment controversy and the mafia's playbook on pushing back against charges leveled against it.

"When I prosecuted the mob, one of their go-to tactics whenever we indicted them was to spend a lot of time trying to show the government did something wrong," Cotter told Insider. "It had nothing to do with the substance of the allegations and everything to do with trying to detract from our case by attacking us. It's illogical and it's what we used to call half a confession."

Read more: A White House official who listened in on Trump's Ukraine call described it as 'crazy' and 'frightening'

President Donald Trump talks to reporters on the South Lawn of the White House, Friday, Oct. 4, 2019, in Washington. (AP Photo/Evan Vucci) Associated Press

Trump takes a page out of the mafia's playbook but 'on a much larger scale'

In the Gotti case, Cotter added, the similarities are even more stark.

"His lawyers accused the prosecutors and the FBI of wrongdoing. They attacked witnesses. They attacked us," he said. "They got protesters to march in front of the courthouse. They went on TV and smeared us with ad hominem attacks. They planted stories in the press. They did everything Trump is doing, but he's doing it on a much larger scale."

At the heart of the latest controversy engulfing the White House is a July 25 phone call Trump had with Ukrainian President Volodymyr Zelensky, during which he repeatedly pressured Zelensky to investigate former Vice President Joe Biden and his son for corruption. Biden is a 2020 Democratic frontrunner and one of Trump's chief political rivals.

The phone call is the subject of an explosive whistleblower complaint that a US intelligence official filed against the president in August. In addition to accusing Trump of abusing his power and violating federal law, it says Trump's personal lawyer, Rudy Giuliani, is a "central figure" in Trump's effort and that Attorney General William Barr "appears to be involved as well."

Trump and his allies have attacked the whistleblower, suggesting the individual is disloyal to the US and committed espionage against Trump, despite the fact that they followed the law when filing their complaint. The president has also repeatedly called for the whistleblower's identity to become public.

A White House summary of the call confirms the main details of the complaint, and Trump's handpicked spy chief testified to Congress that the complaint is "in alignment" with the memo.

Read more: Trump says he's a master dealmaker, but his record of dancing to the tune of foreign leaders says otherwise

The intelligence community watchdog, moreover, deemed the complaint to be "urgent" and "credible." Last week, Trump confirmed the complaint's central allegation — that he wanted a foreign government to investigate a political opponent — when he publicly called for both Ukraine and China to look into the Bidens.

Given these developments, "it doesn't matter who the whistleblower is or what they did," Cotter said. "When someone gives you information, you try to corroborate it. This whistleblower said they think the president essentially tried to bribe a foreign official to get dirt on his political rival. And now we have the body — the body is the White House memo where the president's own words prove what he was accused of."

'You don't fight on the other guy's ground, you define what the debate is going to be about'

Roy Cohn (L) and Donald Trump attend the Trump Tower opening in October 1983 at The Trump Tower in New York City. Sonia Moskowitz/Getty Images

This isn't the first time Trump's actions have prompted comparisons to mob tactics. Indeed, one of his longtime confidants was none other than Roy Cohn, the notorious fixer that Sen. Joseph McCarthy hired as his chief congressional counsel while trying to root out communists in the 1950s.

Following McCarthy's downfall and his own resignation from the panel, Cohn went on to private practice in New York, where he represented several high-profile mafia figures, like Gotti, Carlo Gambino, and Tony Salerno.

Cohn and Trump met in the 1970s while the Trump Organization was being sued by the Justice Department for denying housing to African-American applicants. The Atlantic's George Packer noted that after the two met, Trump became Cohn's client and protégé and that they won the case by employing many of the same strategies the mafia uses: counterattacking, raising phony and misleading charges, and refusing to give an inch or admit any wrongdoing.

"Roy would always be for an offensive strategy," the longtime GOP strategist and Trump confidant Roger Stone said in the documentary film, "Where's My Roy Cohn?"

"These were the rules of war. You don't fight on the other guy's ground, you define what the debate is going to be about," Stone added. "I think Trump would learn that from Roy."

Read more: House Democrats are so afraid Trump allies will expose the whistleblower that they might mask the person's voice and face during testimony

'It's not about anything else except the boss'

Manuel Balce Ceneta/AP

Trump's mafia-style tactics haven't gone unnoticed by those around him.

Michael Cohen, Trump's longtime former lawyer, testified to Congress in February that the president runs his operation "much like a mobster would do."

Former FBI director James Comey has frequently compared the president to a mob boss and said that when he first met Trump, he couldn't shake the feeling that he felt he was dealing with the Cosa Nostra.

"It's not about anything else except the boss," Comey said while giving a talk at the 92Y in New York City last year. "It's a fear-based leadership."

FBI investigators who examined whether the Trump campaign conspired with Russia during the 2016 election also treated the case like they would an organized-crime syndicate, particularly through the use of cooperating witnesses.

"The higher you go, the more insulated those people are," Elie Honig, a former federal prosecutor from the Southern District of New York who successfully prosecuted more than 100 members and associates of the Sicilian Mafia, told Insider last year. "So the best way to penetrate that closed inner circle is by flipping people, and flipping them up."

Honig said he once nailed a case by flipping someone who was the driver for a more powerful person in the organization.

"That led us right up the chain," he said. "And you can see that happening in the Russia investigation."

The first plea deal the former special counsel Robert Mueller's office announced was that of George Papadopoulos, who served as an early foreign policy aide to the Trump campaign. Next, he looped in Michael Flynn, the former national security adviser who admitted to lying to the FBI.

In February 2018, Rick Gates, the former deputy chairman of the Trump campaign, announced that he would be pleading guilty and cooperating with the special counsel. Gates' cooperation led prosecutors upstream, and his courtroom testimony against former Trump campaign manager Paul Manafort helped them successfully convict Manafort on eight counts of financial fraud last August.

Manafort, too, eventually pleaded guilty to additional criminal charges and began cooperating with prosecutors.

And the continued cooperation of Cohen — who is currently serving a three-year prison sentence after pleading guilty to campaign-finance violations, tax evasion, bank fraud, and lying to Congress — will likely help prosecutors get information on an even bigger fish.

The Russia investigation has formally ended. But Mueller spun off more than a dozen criminal matters stemming from his investigation to other US attorneys' offices across the country. The vast majority of those matters remain under wraps.