"I simply do not think it is right for me to ask the voters who have put their faith in me all these years ... to continue voting for me one more time while there is a cloud hanging over my head," a somber Fumo said.
When he leaves office at the end of the year, Fumo will have completed three decades in office, a career in which he earned renown as a political powerhouse and a brilliant tactician with a fiery temper that occasionally erupted in profanity-laced explosions.
His political future was cast into doubt last year when federal prosecutors in Philadelphia unveiled a 139-charge indictment that he defrauded the state Senate, a seaport museum and a nonprofit by using their staff and assets to do his personal and political work.
Prosecutors allege that Fumo took trips and ordered elaborate office renovations that were paid for by a nonprofit charity in his district that is run by his allies and funded by money he won in a regulatory settlement with the Philadelphia-area electric utility.
Despite its charity status, the nonprofit group, Citizens' Alliance, also allegedly funded political activities, including a poll and a lawsuit against one of Fumo's political rivals. As a board member of the Independence Seaport Museum in Philadelphia, Fumo took free pleasure cruises on its yachts, despite the organization's code of ethics that barred directors from personal use of its property, the indictment said.
He routinely used Senate employees to attend to matters at his Victorian-style mansion in Philadelphia, a beach house in New Jersey and a farm outside Harrisburg, the indictment said. Fumo allegedly ordered Senate employees to destroy e-mail correspondence on his computers after he became aware of the investigation.
A trial is scheduled for September; Fumo maintains his innocence. He has beaten criminal charges twice before, including once when the trial judge vacated the conviction in 1981.
A banker's son from South Philadelphia, Fumo entered the Senate in 1978. He is described by allies as pugnacious and principled, winning battles because he worked harder and understood the levers of political power better than everybody else.
Even Republicans, who control the Senate, acknowledge that Fumo could manipulate the political process so effectively that he usually got what he wanted.
He brokered the passage of the 2004 law that legalized up to 14 slot-machine casinos and put Pennsylvania on track to become one of the nation's biggest gambling states. While much of the state's take from gambling is earmarked for cutting taxes, Fumo won enough votes by ensuring that some of the money was targeted for special purposes in the districts of Republican senators who otherwise would have opposed the bill.
A prolific fundraiser, he worked hard to elect aspiring judges and legislators, but also expected loyalty from them. Such was his profile that most, if not all, statewide candidates, including presidential hopefuls, sought his backing.
"He did so many things for so many different people in so many places, he was able to call in chits," said Pennsylvania's Democratic party chairman, T.J. Rooney. "And when he got behind a candidate, that candidate was automatically credible."
Fumo's political acumen worked beyond Pennsylvania too.
Meeting with Russian officials on a trade mission in 1986, he won visas for two Russian Jews who had relatives in his Senate district to emigrate to Israel. But before asking outright for the visas, he first coaxed the officials into boasting about their ability to cut through red tape and get things done.
The visas were ready the next day, recalled Republican Sen. Gibson Armstrong of Lancaster County, who sat in on the meeting.
"It was amazing," Armstrong said. "He used the guy's ego and power to his advantage."