Rudy Giuliani has dined out for years on his aggressive use of Rico, the Racketeer Influenced and Corrupt Organizations Act, which he wielded with dramatic effect against New York mobsters in the 1980s.

For his pains, he was granted an award by the Italian government. Later, as New York City mayor, he turned his use of the anti-racketeering law into a vote-getter, presenting himself as the hero of Rico.

As an in-joke, he handed the keys of the city to the cast of the Sopranos. Then he went on Saturday Night Live and bragged about “sticking it to organised crime”.

He may not be laughing so loudly now.

On Monday night Giuliani, Donald Trump and 17 other co-defendants were slapped with organised crime charges in Georgia under the state’s Rico law, for allegedly having been part of a vast conspiracy to overturn the 2020 presidential election. The hero of Rico had been hoist with his own petard.

The grand jury indictment charges all of the 19 co-defendants, Giuliani included, with “racketeering activity” in Georgia and other states. It alleges that they acted together as a “criminal organisation” which engaged in illegal activities including forgery, filing false documents and conspiracy to defraud the state.

The irony that Fani Willis, the district attorney of Fulton county who is leading the prosecution, chose to hit the hero of Rico with a Rico rap has not been lost on Giuliani watchers. Appointed as US attorney for the southern district of New York in 1983, he did not so much invent the anti-racketeering law, which was enacted in 1970, as become an early adopter in its use against organised crime.

His most famous case, the 1986 prosecution known as the “commission” case, targeted eight defendants at the very top of one of the most powerful New York mafia families. “The verdict reached today has resulted in dismantling the ruling council of La Cosa Nostra,” Giuliani said after the convictions were secured in a 10-week trial.

His victory demonstrated the huge potential of Rico as a prosecutorial tool against crime gangs. Instead of the traditional approach of picking out individual foot soldiers, one arduous case at a time, Rico allowed prosecutors to take out the entire upper leadership of the criminal enterprise in a single devastating blow.

Giuliani may well be ruing his much-vaunted success. The “commission” case put Rico on the map, and since 1986 it has spread widely at both a federal level and across state jurisdictions – Georgia included.

The Fulton county indictment makes a specific point of highlighting aspects of Giuliani’s behavior in the thick of the 2020 election that it alleges amounted to racketeering. It recounts some of the more lurid lies that he disseminated in front of the Georgia lawmakers in an attempt to persuade them to subvert Joe Biden’s electoral victory in the state.

The falsehoods included his claim that 10,315 dead people had voted in the presidential election; that fraudulent ballots had been counted five times in a counting center; and that two poll workers, Ruby Freeman and her daughter Shaye Moss, had passed around USB ports “as if they’re vials of heroin or cocaine” seeking to infiltrate the voting machines.

In July, Giuliani admitted in court that his comments about Freeman and Moss were false. Moss testified to the January 6 committee that the supposed USB ports she had exchanged with her mother were in fact ginger mints.

The indictment presents all these incidents not just as lies, but as the actions of a member of a criminal racketeering enterprise, designed to further the conspiracy and achieve its goal of keeping Trump in the White House despite his electoral defeat. That Giuliani should have exposed himself to a Rico prosecution in this way is puzzling to those who have followed his legal career.

“Of all the defendants, Giuliani knows Rico better than anyone, he lived with it for decades,” said Michael Discioarro, a former prosecutor in the Bronx. “Rudy knows darn well where the line is drawn, and it’s surprising to me that he even put himself in that position.”