Former FBI Director James B. Comey Jr. has been making the rounds with the stunning observation that President Donald J. Trump behaved much liked the mob bosses he put on trial in his days as a federal prosecutor in Manhattan.

During his time in the White House, Comey says he felt the president repeatedly trying to make him a member of his corrupted inner circle when he famously asked the FBI director for loyalty.

In his last conversation with Comey on April 11, Trump told him: “I have been very loyal to you, very loyal, we had that thing, you know.” We had that thing. That thing of ours. It’s literally a translation of La Cosa Nostra, which is how  members of the American Mafia describe their organization.

Comey tells us a fundamental truth about the man we have elected to the most powerful office in the world: Donald Trump was a mob-friendly businessman.

Mobsters were Trump’s customers, his friends, his business partners, and his employees. His towers in New York and Florida catered to Mafiosi by facilitating money laundering through untraceable LLCs. As I found in researching my book, Trump/Russia: A Definitive History, Trump’s personal attorneys, including Michael D. Cohen, had connections to organized crime, which Trump likely viewed as an asset.

By the time Trump descended the escalator at Trump Tower to announce what seemed like a quixotic quest for the presidency, his relationship with organized crime — Russian and home-grown — was already several decades old.

Trump Tower, his home and signature development, was built with concrete poured by  a company secretly owned by Mafia bosses Anthony “Fat Tony” Salerno and Paul Castellano, both of whom happened to be clients of Trump’s heavy-lidded lawyer, Roy Cohn.  When concrete workers went on strike in the summer of 1982, Trump’s buildings were the only ones exempted.

Trump isn’t the only president to have ties to organized crime, but the critical difference between presidents past and the current one is that Trump may be the only president to have been helped by criminals with ties to criminals from a foreign power.

Over time, Trump graduated from the American Mafia to the Russian Mafia. This association began in 1984 when the FBI learned that Trump had made the acquaintance of a Russian criminal named David Bogatin and talked him into purchasing five apartments for nearly $6 million with money he had earned by scamming New York state out of gasoline tax revenue in a partnership with the Colombo family.

Trump’s Taj Mahal casino in Atlantic City became a favored destination for Russian gangsters, who were regularly visiting to launder money. One patron was a man named Vyacheslav Ivankov, who was a vor, the rough equivalent of a Mafia “Godfather.”  FBI files I obtained show that agents tracked him to the Taj Mahal and noted that he often arrived by limousine. Curiously, the FBI also tracked Ivankov to Trump Tower, but could never figure out what he was doing there.

There were all sorts of underworld connections at the Taj Mahal. One vice president at the Taj Mahal was described by  investigators as an associate of an international heroin syndicate based in Hong Kong. When New Jersey tried to kick him out , Trump sent the Taj Mahal  president to publicly defend him.

Trump also built a close relationship with  Felix Sater, who had once been convicted in a Mob-linked Wall Street scam and was serving as an undercover informant for U.S. intelligence. Sater would spend years trying to fulfill Trump’s dream of a tower in Moscow with his name on it, and the two men grew close that Trump asked Sater to look after his children during one of their regular trips to Moscow. Yet, when Sater’s criminal past was exposed, Trump, claimed “one of the great memories of all time,” seemed to be having trouble recollecting who Sater was. He acted, as he often has as president, as man with something to hide.

Trump shared with mob bosses another characteristic that Comey didn’t note: His hatred of law enforcement.

There’s a simple explanation why the president has repeatedly attacked and humiliated Comey and the leadership of the FBI. It’s because having spent their careers chasing cons and grifters, FBI agents know one when they see one. The shady business dealings of the Trump Organization have been on the radar of the U.S. law enforcement and intelligence community for a long time, and Trump knows it. As the net closes in and the pressure mounts, his attacks on his own FBI and Justice Department will continue to mount.

I cannot say it better than former CIA Director John Brennan who recently warned the president on Twitter: “When the full extent of your venality, moral turpitude, and political corruption becomes known, you will take your rightful place as a disgraced demagogue in the dustbin of history.”