Ligambi, 71, is accused of running La Cosa Nostra for the past 12 years, heading a South Philadelphia enterprise deeply engaged in illegal gambling, loan sharking, sports betting and other crimes.
The indictment suggests La Cosa Nostra during his reign focused on making money, not killing off rivals. But prosecutors argued that Ligambi relied on his reputation - and the threat of violence - to collect debts.
In one example, Ligambi wrested control of 34 illegal poker machines from their owners to snag the proceeds from the profitable machines, prosecutors said.
"In a successful extortion ... the (victims) do what they are told," Assistant U.S. Attorney David Troyer said. "Nobody gets hurt."
He argued that Ligambi could send orders electronically if released, putting cooperating witnesses in danger. Evidence in the case includes seven such mob insiders, along with 14,000 taped conversations from the past decade, he said.
Defense lawyer Edwin Jacobs Jr. argued that neither the indictment nor government excerpts of those tapes allege any violence. And he said his client's only serious conviction, for gambling, is two decades old.
"We're not going to see hollow-point bullets, we're not going to see handguns," Jacobs said. "If they have a strong case, they have a gambling case, they have a financial case."
Ligambi was once convicted of murder in state court, but the verdict was overturned and a second jury acquitted him.
"How youse doin'?" Ligambi shouted to his wife and other supporters as he entered the courtroom in handcuffs and a prison jumpsuit Wednesday.
He has been in custody since his arrest in late May. The lengthy indictment names 12 others as co-defendants.