WASHINGTON — I first met Rudy Giuliani in 1986 when I was a Times reporter writing about corruption cases in New York. Gotham was awash in so much municipal sleeze, a detective joked that city employees were streaming into the F.B.I. office with their hands up.

Giuliani, the U.S. attorney for the Southern District of New York, got in a kerfuffle with Robert Morgenthau, the storied Manhattan district attorney who was a model for the D.A. in “Law & Order,” because Rudy considered the local prosecutor to be superfluous, so he wasn’t sharing information.

Giuliani, 41, was already renowned as a scourge of organized crime. (The next year he would become the scourge of Wall Street, perp-walking white-collar criminals in handcuffs in tableaus of virtue conquering vice, even though the charges sometimes failed to stick.)

Morgenthau favored a sweater with a hole in it. Giuliani was bandbox-perfect, feral and ready to pounce. Morgenthau had an understated tenacity. Giuliani was like a cult leader among acolytes.

He grew up thinking he would be a priest — until he decided he didn’t want to be celibate. When I met him, he was still speaking passionately about good and evil, right and wrong. His eyes gleamed when he talked about routing blackguards who had breached the public trust. He was following a Thomas Dewey model: Clean up corruption and parlay that into higher office.

The phone rang as I came into the paper the morning my story ran. Giuliani was demanding to talk to my editor — the story made him seem holier-than-thou!

He didn’t know how good he had it. Now he just seems crazier-than-thou. It’s a Puccini opera, really, about an opera-loving federal prosecutor and heroic mayor who spirals into lawlessness, as well as multiple divorces, depression, drinking, money problems, sexual harassment claims, Cameo cameos and “Borat” humiliation.

Giuliani went from cleaning up corruption to ginning up corruption, from crimebuster to criminal defendant in Georgia and unindicted “Co-Conspirator 1” in D.C. Rudy, the prosecutor who made his reputation aggressively pursuing RICO cases, is now Rudolph William Louis Giuliani, a defendant in the Georgia RICO case about the deranged plot to steal the election.

We have seen many cases of mobsters turning state’s evidence for prosecutors. But now we have the rare experience of seeing a prosecutor turn into a mobster.

After all those years spent prosecuting the Five Families in New York, Giuliani surrendered himself to the lamest mob boss there ever was: Don Trump.

We saw the coup attempt play out, but it’s startling to see the Georgia indictment refer to “this criminal organization,” “members of the enterprise,” “corruptly solicited” and “acts of racketeering activity.”

Trump, mentored by mob lawyer Roy Cohn, always loved acting like a mobster, playing the faux tough guy, intimidating his foes, swanning around like John Dillinger, Al Capone and John Gotti. He told Timothy O’Brien, the author of “TrumpNation: The Art of Being the Donald,” that he admired Gotti because the mobster sat through years of trials with a stone face. “In other words, tough,” Trump said.

As Trump’s former lawyer Michael Cohen testified to Congress, Trump ran his family business “much like a mobster would do,” using “a code,” letting capos do the dirty work and expelling rats.

“Trump both fetishized mobsters and did business with them,” O’Brien told me. “The way he fetishizes mobsters informs this fascination he has about Putin and Kim Jong-un. He loves ‘bad-ass’ guys who roll like they want to roll. He sees himself the same way.”

True to his longtime practice of stiffing the help, Trump is turning a deaf ear to Giuliani’s desperate pleas, in a tin-cup trip to Mar-a-Lago, to pay his legal bills.

Desperate to stay relevant, Giuliani made himself Trump’s legal button man, pressing the conspiracy theories his boss wanted to hear on Ukraine and the Bidens, and then on election fraud. Giuliani can take credit for helping spur both Trump impeachments.

As the great Village Voice reporter Wayne Barrett wrote in his 2000 book, “Rudy: An Investigative Biography of Rudolph Giuliani,” Rudy had his own family history with wiseguys. Although Giuliani’s father, Harold, taught him to hate the mob, some cousins had mob connections. Barrett wrote that Rudy’s father had broken legs and smashed kneecaps for his brother-in-law’s loan-sharking in the ’50s. Barrett also revealed that Rudy’s dad went to Sing Sing for robbing a milkman at gunpoint.

Rudy told The Times’s Sam Roberts his family moved to Long Island from Brooklyn to avoid his mobbed-up relatives, and it was a reason he got into law enforcement.

“Rudy wants to be the mob slayer and then he winds up doing mobster-like things and getting in bed with a wannabe mobster,” O’Brien said, “and neither one of them can shoot straight, and they end up getting in trouble with the law. It’s a dime-store psychodrama that is both comic and grotesque at the same time.”