The campaign strategy that has allowed him to become a contender in these elections is a simple one: please the masses by throwing around cash.
Berlusconi has promised to give back an unpopular property tax imposed by Monti as part of austerity measures. Even his purchase of star striker Mario Balotelli for his AC Milan soccer team was widely seen as a ploy to buy votes. Berlusconi has also appealed to Italy's right-wing by praising Italy's former fascist dictator Benito Mussolini during a ceremony commemorating Holocaust victims.
The most recent polls show Bersani in the lead with 33% of the vote, against 28% for Berlusconi's coalition with the populist Northern League. Grillo's 5 Star movement was in a surprise third place, with 17% support, while Monti's centrist coalition was notching 13%. The COESIS poll of 6,212 respondents had a margin of error of plus or minus 1.2 percent.
Pollster Renato Mannheimer said among his biggest clients heading into the elections were foreign banks seeking to gauge whether to hold or sell Italian bonds.
"They are worried mostly about the return of Berlusconi," Mannheimer said.
Uncertainty over the outcome of the vote has pushed the Milan stock exchange down in the days running up to the vote and bumped up borrowing costs, as investors express concern that Italy may back down from a reform course to pull the country out of recession.
Mannheimer said many undecided voters -- who comprise around one-third of the total electorate -- identify with the center-right, and that may help Berlusconi. He said that the undecided vote may also tilt heavily toward Grillo's protest movement.
The professorial Monti looked uncomfortable at first as a candidate but has recently warmed to the role. Like the others, he has not shied away from name calling, warning that Berlusconi is a "charlatan" and saying his return would be "horrific."
Bond analyst Nicholas Spiro said the election "will deliver the most important verdict on the eurozone's three-year-old austerity focused policies."
But he is betting on a period of political instability after the vote.
"An upset victory by Mr. Berlusconi may be markets' nightmare scenario," he said, "but the prospects for a stable and harmonious Bersani-Monti coalition government -- still the mostly likely outcome in our view -- are bleak."