"He's not going away; he's going to continue to make Italian life very difficult for as long as he can," says Alexander Stille, the author of The Sack of Rome: How a Beautiful European Country with a Fabled History and a Storied Culture Was Taken Over by a Man Named Silvio Berlusconi.
Berlusconi has shown no sign of exiting the political scene after Italy's highest court found him guilty of tax fraud on August 1st.
While some observers thought the summer verdict would see him shy away from frontline politics, he took the opposite approach. The three-time prime minister first decided to rebrand his People of Freedom (PdL) party as Go Italy (Forza Italia), reigniting the party name which swept him to power in 1994.
When the move had little impact on political life, Berlusconi at the end of September attempted to force his five ministers to resign from the coalition government. The plan backfired when Angelino Alfano, deputy prime minister and until then Berlusconi's protégé, rebelled and the government stood firm.
The aggressive style adopted by Berlusconi in recent months has been his style throughout his business and political career.
"He will bite and scratch and claw to protect his interests, that's not going to change," Stille tells The Local.
While today's vote has been anticipated since the August verdict, Stille says it has likely come as a shock to Berlusconi.
"He's operated on the assumption that the law doesn't apply to him...His disconnection from reality has increased with passing years and he is surprised that finally one of these cases went through all the courts and he has to take the consequences," he says.
Berlusconi is currently appealing a number of other convictions, including leaking a confidential police wiretap to damage a political rival. He is also due to be tried for bribing a senator to join his party.
The billionaire himself decries the accusations and convictions as a plot against him by leftists judges, while Stille says Berlusconi "dared to do what others might not have dared to do".
Berlusconi's success as a politician can be traced to his early career as a property developer, which saw him go from a middle-class banker's son to the country's richest man.
"Hard work and daring, above all, have always been a part of his career as an entrepreneur, but I would say string pulling has always been a part of it," says Stille.
After large-scale development projects in Milan, Berlusconi went on to build a television network and snap up football club AC Milan.
The latter "made him a star" according to Stille, who says Berlusconi acted "unscrupulously" in his business deals and succeeded by courting the powerful.
"He understood that’s the way the game is played and was very savvy about it. It’s not about having political beliefs, it’s about having political connections," Stille says.
But after two decades in politics, Berlusconi's political connections have been severely weakened in recent weeks. Earlier this month, Alfano broke away from Berlusconi and formed his own New Centre-right (NCD) political group.
With Alfano determined to stand by centre-left Prime Minister Enrico Letta, Berlusconi is looking increasingly isolated ahead of the Senate vote.
But whatever the outcome of Wednesday's vote, Berlusconi "is still enormously rich and powerful", Stille warns, and is not likely to go quietly.