Prosecutors have found racketeering laws to be powerful tools in targeting not only foot soldiers in a criminal enterprise, but also high-level decision makers.For more than 50 years, prosecutors have relied on a powerful tool to take down people as varied as mafia capos, street gangs like the Crips and the Bloods, and pharmaceutical executives accused of fueling the opioid crisis.Now a prosecutor in Georgia is using the state’s version of the Racketeer Influenced and Corrupt Organizations Act, better known as RICO, to go after former President Donald J. Trump, who along with 18 of his allies was indicted on Monday on charges of participating in a wide-ranging conspiracy to overturn the results of the 2020 election in Georgia.One power of RICO is that it often allows a prosecutor to tell a sweeping story — not only laying out a set of criminal acts, but identifying a group of people working toward a common goal, as part of an “enterprise,” to engage in patterns of illegal activities.Fani Willis, the district attorney in Fulton County, Ga., is using a RICO indictment to tie together elements of a broad conspiracy that she describes as stretching far outside of her Atlanta-area jurisdiction into a number of other swing states, a legal move made possible by the racketeering statute. Her investigation also reached into rural parts of Georgia — notably Coffee County, where Trump allies got access to voting machines in January 2021 in search of evidence that the election had been rigged.Signaling its breadth, the indictment brought Monday night laid out a number of ways the defendants obstructed the election: by lying to the Georgia legislature and state officials, recruiting fake pro-Trump electors, harassing election workers, soliciting Justice Department officials, soliciting Vice President Mike Pence, breaching voting machines and engaging in a cover-up.“RICO is a tool that allows a prosecutor’s office or law enforcement to tell the whole story,” Ms. Willis said at a news conference last year.Her challenge will be to convince jurors that the disparate group of 19 conspirators charged in the indictment — including a former president and a local bail bondsman, a White House chief of staff and a former publicist for Kanye West — were all working together in a sprawling but organized criminal effort to keep Mr. Trump in power.State and federal prosecutors have found that they can use RICO laws to effectively make such arguments, and Ms. Willis has done it before. So has Rudolph W. Giuliani, one of the defendants, who made his name trying racketeering cases against mafia families decades ago as a federal prosecutor in New York. Rudolph W. Giuliani, at the Fulton County courthouse in Atlanta last year.Nicole Craine for The New York TimesClark D. Cunningham, a law professor at Georgia State University, said the indictment “shows the incredible power brought to bear against Trump by using Georgia’s racketeering law,” noting that in addition to the 19 people charged, it encompassed “as many as 30 unindicted co-conspirators — over 160 separate acts in all.”But RICO laws have their detractors. Some critics say that the laws have granted too much power to prosecutors, allowing them to indict dubious members of “organizations” that are in some cases barely organized.“Because RICO is so expansive, and so open, as a tool, it allows people to be caught in its dragnet that are nothing like the people who were originally intended” when the laws were first developed more than 50 years ago, said Martin Sabelli, a past president of the National Association of Criminal Defense Lawyers.Another potential pitfall for a big RICO case is that it may become too complex for jurors to follow. As Michael J. Moore, the former U.S. attorney for the Middle District of Georgia, put it on Monday night: “When you fish with too big a net, you risk getting tangled up yourself.”Some of the defendants were already accusing Ms. Willis of overreaching. A spokeswoman for Jeffrey Clark, a former Justice Department official who was charged in the case, said Ms. Willis was “exceeding her powers by inserting herself into the operations of the federal government to go after Jeff.”Mr. Trump’s legal team said, “We look forward to a detailed review of this indictment which is undoubtedly just as flawed and unconstitutional as this entire process has been.”Mr. Trump and his allies have argued that their efforts to challenge his 2020 election loss in Georgia were well within the bounds of the law. Indeed, Mr. Trump has been laying the groundwork for his defense for months, arguing repeatedly that there was nothing illegal about his now-famous call to Brad Raffensperger, Georgia’s secretary of state, on Jan. 2, 2021.In that call, Mr. Trump told Mr. Raffensperger he hoped to “find” the 11,780 votes he needed to win Georgia.But the RICO indictment forces Mr. Trump to push back against a broader allegation — that he was part of a multipronged criminal scheme that involved not only calls to state officials, but the convening of bogus pro-Trump electors, the harassment of Fulton County elections workers, and false statements made by Trump allies, including Mr. Giuliani, before state legislative bodies.The Georgia State Capitol in Atlanta, where the fake electors gathered in 2020.Audra Melton for The New York TimesIn Georgia, RICO is a felony charge that carries stiff penalties: a potential prison term of five to 20 years, a fine or both.Racketeering statutes are an outgrowth of New York City’s long history of combating corruption and organized crime. The word “racketeer” itself is derived from the “racket” at boisterous Tammany Hall fund-raising dinners where it was an expectation, among crooked politicians, that anyone who hoped to get a piece of city business would buy tickets.Under Mr. Giuliani’s leadership in the 1980s, the U.S. attorney’s office for the Southern District of New York used RICO to prosecute powerful mobsters like Anthony “Fat Tony” Salerno of the Genovese crime family, and Anthony “Tony Ducks” Corallo of the Lucchese family. But Mr. Giuliani also used the federal statute to prosecute white-collar business cases.Ms. Willis may rival Mr. Giuliani in her deep well of experience with RICO charges. She made her name as an assistant district attorney by bringing a sprawling RICO case against educators in the Atlanta public school system in 2013 in the wake of a cheating scandal, and has used Georgia’s version of the law repeatedly since then.In the 2013 case, a group of Atlanta educators were accused of inflating standardized test scores and giving a false sense of academic progress. At the time, there was concern that the state was applying a law known for targeting the mob to a group of modestly paid public schoolteachers, most of whom were Black.“I think it’s overkill,” the Atlanta lawyer Bruce H. Morris told The Los Angeles Times. “RICO was originally designed for organized crime.”Ms. Willis has said defending the integrity of the education system — and children’s right to an education — was paramount. The trial ended with 11 defendants being found guilty of racketeering, with some convicted of other crimes.After being elected Fulton County’s top prosecutor in 2020, she has continued to be aggressive in using RICO to prosecute other cases, particularly in her fight against street gangs. The best known is the ongoing RICO conspiracy case against the group Young Slime Life, headed by the Atlanta rapper Jeffery Williams, who performs as Young Thug.Fulton County District Attorney Fani Willis made her name as an assistant district attorney by bringing a sprawling RICO case in 2013.Audra Melton for The New York TimesThe indictment charges that members of the group, known as YSL, committed the crime of conspiracy to violate the RICO act, and that certain members are responsible for crimes like murder, aggravated assault and armed robbery. Defense attorneys maintain that the group is merely a musical collective.In an analysis of the case for the pop culture website Complex, Andre Gee, a music and culture writer, blasted Ms. Willis for wielding RICO as an overly broad dragnet.“It’s an ugly, precedent-setting maneuver in the war on rap that can only happen because the law allows her to be creatively predatory with their definition of a ‘corrupt organization,’” Mr. Gee wrote.Some experts have argued that applying RICO charges in a criminal case allows prosecutors to use the laws’ often stiff penalties to pressure defendants marginally connected to criminal groups to take plea bargains. In the YSL case, Ms. Willis’s office obtained pleas from a number of defendants, securing admissions along the way that the group was indeed a criminal street gang.The Young Thug case, taking place in the same courthouse that may eventually host Mr. Trump, has shown how unwieldy a large racketeering case with multiple defendants can be: Jury selection, which began in January, has yet to be completed, and has been rife with hiccups and scandals.Noting that Ms. Willis is hoping for a trial within the next six months, Christopher Timmons, an Atlanta trial lawyer and former prosecutor experienced in RICO cases, said the timetable seemed to be “ambitious.”“Six months to start a RICO trial is lightning fast,” Mr. Timmons said in an email early Tuesday. “They usually take a year to put together. That suggests the D.A.’s office walked into the grand jury room knowing what their case will look like at trial.”Even though RICO laws now go far beyond mob-busting, their origins in fighting the New York mafia can still work against defendants in the court of public opinion.But a good defense lawyer can sometimes use the laws’ association with the mob to their client’s advantage. That was the case in 2013, when one of Mr. Trump’s current lawyers in Georgia, Drew Findling, was defending a sheriff in the suburbs of Atlanta who had been accused of corruption and was facing state RICO charges.In his closing argument at trial, Mr. Findling, according to The Atlanta Journal-Constitution, ridiculed state prosecutors for not reaching out to federal authorities if they truly believed they were dealing with a criminal on a par with the nation’s most infamous gangsters.His client was acquitted. More