By Barry Moody
ROME (Reuters) - After 17 years, Italians finally seem to have had enough of Silvio Berlusconi.
Massive defeat in four referendums on nuclear energy, water privatization and trial immunity for ministers last weekend were the biggest blow in an annus horribilis for the prime minister that many analysts say signals the start of a new era.
"He will not come back up. We cannot say how long the descent will take but certainly it will be fairly rapid," Professor Gianfranco Pasquino of Bologna university told Reuters.
Some 27 million Italians voted overwhelmingly in favor of referendums that Berlusconi had urged them to boycott. His humiliation opened a period of deep uncertainty and has generated what could be risky pressure to ease fiscal policy.
The Italian prime minister's frequent gaffes and off-color jokes have given him a dubious international reputation that obscured his undoubted skills as a politician and communicator.
Since bursting on to the scene in 1994, filling a vacuum on the center-right created by the destruction of the Christian Democrat party in a huge corruption scandal, he has dominated Italian politics and headed three governments.
But the magic has finally evaporated, leaving the 74-year-old premier battered from all sides and ridiculed for the "Bunga Bunga" sex parties that magistrates say he hosted with starlets and prostitutes.
"The Magic Flute is Broken," read the headline on a frontpage editorial in the left-leaning Repubblica daily after the referendums, one of which -- on trial immunity -- was interpreted as a very personal vote against Berlusconi.
They followed shock defeats in local elections last month which included losing his hometown of Milan -- Italy's financial capital -- and the southern city of Naples.
Those setbacks in turn followed the start of four concurrent trials against him on charges of fraud, corruption, having sex with an underage nightclub dancer and trying to cover it up -- the latter lurid scandal damaging his core conservative support.
BERLUSCONI'S POLITICAL ERRORS
Berlusconi's own tactics in turning the local elections into a personal vote and obsessively complaining about left-wing magistrates, then his invitation to supporters to boycott the referendums instead of mobilizing a vote against them, were major political errors from the former master.
The defeats have greatly increased tensions between Berlusconi's PDL party and the pro-devolution Northern League on which he depends for survival, although its own weakness after the votes suggests it cannot jump ship immediately.
The government's desperation to win back popularity has generated pressure for tax cuts and more spending, something strongly rejected by Economy Minister Giulio Tremonti, who is credited with shielding Italy from the global economic crisis.
Such cuts are seen as a potential recipe for disaster in one of the world's most indebted countries, where Berlusconi's early promises to liberalize and stimulate the deeply stagnant economy remain unfulfilled, to the dismay of business leaders.
Berlusconi is currently being kept afloat by the Northern League's own limited room for maneuver and disunity in the center-left opposition, which is not keen for elections yet.
Open revolt is also unlikely yet in the PDL because it is built entirely around him, with no mechanism for succession.
But a wide spectrum of analysts predict early elections next spring, a year ahead of schedule, and suggest Berlusconi will not be the chosen leader of the center-right, perceived by many supporters as more of a liability than the asset he once was.
Berlusconi, one of Italy's richest men, has been counted out before, only to bounce back, but few believe he can recover this time.
"The message coming out from the country is that this is a page people want to turn ... the likelihood of a vote in spring 2012 is very, very high," said Professor Franco Pavoncello of Rome's John Cabot university.
An opinion poll on Repubblica's website on Wednesday showed 60 percent of those surveyed with little or no trust in him.
Another, in Corriere della Sera, indicated that 20 percent of PDL voters and a full 50 percent of League supporters had voted in the referendums despite calls by both Berlusconi and League leader Umberto Bossi to stay away.
For now all eyes are on a congress of the Northern League in Pontida, in Lombardy, on Sunday when Bossi will face great anger from his supporters, and a probable confidence vote on the government in parliament on June 22.
The League is likely to push for a withdrawal from the NATO offensive in Libya, measures to stop a wave of illegal immigration from North Africa, and tax cuts as the price of its continued support.
However, analysts say the League would fare badly in an election if it brought down the government now so it is likely to wait several months and then even stand as an independent party outside a governing coalition.
"There is a good possibility that the League will jump ship and go it alone. If they go in as his coalition they will get screwed again," said Professor James Walston of the American University in Rome.
Whatever happens, an era dominated by Berlusconi in Italy's so-called Second Republic seems likely to end. "The post '93 system has probably exhausted itself. The political system has to be rejuvenated, restructured, because this way we are not going to get very far," Pavoncello said.