As Silvio Berlusconi sought to explain his decision this week to heed calls to resign in the midst of a mounting debt crisis, the man who ruled Italy for the better part of two decades turned to the words of Il Duce.

Berlusconi compared his sense of betrayal and isolation after being asked to step aside, even by some of his lieutenants, to musings Benito Mussolini once wrote in letters to a lover. “At a certain point he says: ‘Don’t you understand I don’t count for anything anymore?’ ” Berlusconi told the La Stampa newspaper. “I have felt in the same situation.”

That reflection on personal loss during a time of national crisis, many here say, marks a fitting postscript for Western Europe’s most controversial leader. He is set to step down this weekend, likely leaving a technocrat, Mario Monti, scrambling to form an interim government that will attempt to restore shattered investor confidence in Italy and prevent a catastrophic meltdown of the world’s eighth-largest economy.

A modern-day Caesar who openly denied that the nation was slipping into crisis, Berlusconi’s long survival atop Italian politics divided the nation and bemused the outside world. His exit highlights the failures of Europe’s political class to manage a debt crisis that began in Greece, spread to Portugal and Ireland, and is threatening to engulf far more massive Italy.

As he departs, the 75-year-old media tycoon and playboy politician leaves behind a nation where the buzzwords of the day have tellingly changed. Once, talk shows and radio programs here could not get enough of “bunga bunga” — a phrase Berlusconi is said to have learned from Moammar Gaddafi to describe racy parties. Now, Italians are fixated on “il spread” — the dangerously high interest-rate premium Italy is paying to find buyers for its government bonds.

With Italy, a nation saddled with $2.6 trillion in debt, considered too big to bail out, one last-ditch plan being floated here could force every household in the country to cough up enough cash to buy the Italian bonds that many investors now see as too risky. It suggests what observers are calling the irony of the billionaire’s fall, not from sexcapades or corruption charges, but from a debt crisis that now has 60 million Italians — and much of the financial world — on edge.

“Italians are indulgent with our politicians, until they touch our bank accounts,” said Massimo Franco, the economic columnist for the Italian newspaper Corriere della Sera.

“Unfortunately for him,” Franco continued, “I am afraid that Berlusconi will be remembered for prostitutes and money. And for promising a dream of a better Italy that never came true.”

One of Europe’s richest men, Berlusconi rose to power in the 1990s, and Italy would never be the same. He used his vast television empire to maintain his public persona, cultivating a reputation not through serious news and political talk shows but by squeezing in between gossip and recipes on morning and afternoon Italian TV.

His stations lured viewers with buxom women and cheap comedy. At the same time, Berlusconi cultivated a base of pensioners and housewives who responded to his billionaire’s confidence and Italian charm.

As his lurid affairs and rumors of quasi-orgies pushed into the public eye, he stretched the traditional boundaries for how far politicians could openly stray from the doctrines of the Catholic Church. For better or worse, his hedonism upended the conservative conventions of Italian families.

“He changed society in Italy, because he started to show Italians another reality,” said Arianna Montanari, a political sociology professor at Sapienza University in Rome. “Everything was easy, to have money, to have women. You did not have to hide it anymore.”

Departing in slow motion

After longtime allies turned against him, Berlusconi on Tuesday announced he would resign. But he made his departure conditional on the approval of a key budget bill demanded by the European Union and had looked set to stall in part because of his divisive leadership. The bill was set to take weeks to debate, making his offer appear to be a resignation in slow motion that, his critics suggested, might yet be leveraged into another power grab.

But investors punished Italy for that lack of clarity, staging a panicked sell-off of Italian bonds. Under pressure from Italy’s ceremonial head of state, President Giorgio Napolitano, the bill’s approval was dramatically accelerated, with the Senate passing it on Friday and the lower house poised to do the same Saturday. After the vote, on Saturday night or Sunday, Berlusconi will ride to Rome’s lavish Quirinal Palace, a former home of popes, to tender his resignation.

Like his close friend, Russian Prime Minister Vladimir Putin, Berlusconi may leave the halls of power but not wander far. He is pushing his anointed successor, Angelino Alfano, a 41-year-old former justice minister, to be Italy’s next elected leader. Berlusconi will also still be armed with three popular television stations and a fistful of newspapers and magazines.

“He was not thinking about his legacy this week; he was thinking of how he could keep fighting on,” said Pierluigi Bersani, head of Italy’s Democratic Party, its largest opposition force. “Even if he has resigned, he will still be in politics, behind the scenes. He will invent his successors.”

‘He is paying a price’

A politically conservative populist who abolished property taxes, Berlusconi became known for his taste for female adventure and a sense of personal grandeur befitting ancient Rome. On the grounds of Villa San Martino, his estate outside Milan, Berlusconi built an underground mausoleum topped by marble statues and holding 24 niches for family and friends, including a personal sarcophagus for himself.

In 2010, he installed Nicole Minetti, 26, as a provincial legislator. She is now charged with aiding and abetting prostitution by supplying “female guests” for alleged after-dinner sex games.

During at least some of those wild nights, women reportedly danced for the prime minister, chanting “thank goodness for Silvio.” Berlusconi, also in the hot seat for corruption charges, is additionally facing trial on charges of paying a minor — a 17-year-old Moroccan dancer known as “Ruby Heartbreaker” — for sex.

The scandals took a toll on Berlusconi’s popularity, but his affability and slavishly devoted political power base helped him through. Until the debt crisis.

On Friday, his longtime friend Giuliano Ferrara, editor of Il Foglio, called it unfair to place too much blame on Berlusconi, a man he called a “cultural reformer.” Ferrara said Berlusconi had been thwarted by fights with his finance minister, Giulio Tremonti. He also blamed the opposition for being too weak and disjointed to present Italians with a genuine alternative.

“Of course Berlusconi has made mistakes, one million, two million, who knows how many, but he was not the only one,” Ferrara said. “Now he will no longer be prime minister. He is paying a price, and so is Italy.”

Special correspondent Sarah Delaney contributed to this report.