* Bersani's centre left tipped to win general election
* Lacklustre speaker outshone at rally by younger act
* Party speaks warmly of kingmaker Grillo
By Robin Pomeroy
PALERMO, Italy, Feb 20 (Reuters) - A live rock band and a charismatic warm-up act set the stage on Wednesday for the man introduced to Sicilians - whose votes matter more than most in an election in a few days' time - as "Italy's next prime minister".
The American-style build-up meant Pier Luigi Bersani, the leader of the Democratic Party (PD), struggled to make his rhetoric match the occasion, as he addressed the party faithful in a rally in one of two crucial swing regions.
Four days before polls open, Bersani is hoping Sicily, the southern island where a decade ago blanket support for centre-right leader Silvio Berlusconi wiped out the left completely, will swing back his way.
Along with Lombardy in the north, results from Sicily could decide whether the PD - which polls tip to win the lower house of parliament - can get enough seats in the Senate to rule Italy without risk of government collapse.
While Berlusconi promised tax cuts - even to pay some already collected back into Italians' bank accounts - Bersani has repeatedly told voters he rejects "fairy tales" and would stick with policies of Mario Monti's technocrat administration that was formed to pull Italy back from financial collapse.
As the 61-year-old expounded the merits of fiscal rigour - in words that seemed aimed at reassuring the holders of Italy's vast public debt - he appeared to lose the attention of supporters outside Palermo's opera house.
But he had only to invoke Berlusconi, a bogey-man for the left which says he did as much damage to Italy's reputation abroad as to its economy, to wake them up.
"We have heard from Berlusconi promises of 4 million jobs and we are still waiting for the first million from 10 years ago," said Bersani, who derided the media magnate and four-time prime minister as a "pharaoh" and "emperor".
As an antidote to Berlusconi's slick populism, Bersani, a former communist who was industry minister in the last centre-left government which fell in 2008, is seen by his fans as the perfect person to lead the PD back to power.
But taking the stage after the candidate he beat into second place in the primaries, the photogenic 38-year-old mayor of Florence, Matteo Renzi, some PD supporters wondered if they chose the wrong man.
With a stylish open-necked shirt contrasting with balding Bersani's red tie, Renzi flattered Sicilians by telling them their votes were worth twice that of other Italians due to the region's strategic importance.
"It's like you have a double vote," he told the crowd. "It's like you have a joker to play."
Unlike Bersani, who fluffed his attempts to get a crowd response by replying for them - "Will we win or will they win? We will," he said before the audience had time to react - Renzi's timing was spot on.
Reminding Sicilians that Berlusconi took all of Sicily's 61 voting precincts in 2001, helping him to a landslide victory nationally, Renzi raised a roar from the crowd.
"We remember the 61-to-0 of this region. What did they do for Sicily?" he asked, to shouts of "Nothing!".
Sicily already swung back to the left last year, when an openly gay, mafia-bating leftist, Rosario Crocetta, won the regional elections, boding well for the PD when Italians vote on Sunday and Monday.
But if the PD does come first nationally, it is likely to have to govern in coalition with either Monti's centrist grouping or seek to persuade members of the upstart, anti-establishment 5-Star movement to support them.
Led by rabble-rousing comic Beppe Grillo, 5-Star scored 16 percent in an average of final polls published before a pre-election blackout, putting it third after the PD and Berlusconi's People of Freedom.
Potential kingmaker Grillo has ruled out joining a coalition with any of the parties, all of which he brands as dishonest. But that might not exclude the possibility of 5-Star lawmakers supporting a coalition from the outside, and Renzi aimed some of his speech at them and their electors.
"Let me confess, I'm going to out myself. I have been a mad fan of Grillo's shows for years," he said, adding that he also supported the comic's ideas on the environment, technology and reducing the cost of politics.
"There's just one thing. They can talk as much as they like, but they'll never do it, they'll never do it because a protest vote doesn't go anywhere," he said.
PD supporters in Palermo seemed keen on working with 5-Star.
"I think it's a positive movement. It has brought together a lot of people who are unhappy (with politics)," said Cecilia Marescalchi, a 59-year-old local council employee who said the PD had failed to reach the youth.
"Young people feel they are being heard by Grillo, they are attracted to him," she said, admitting that perhaps if the PD has chosen Renzi as their leader, rather than Bersani, it might be getting more of those votes lost to 5-Star.