ROME — Having spent months manufacturing procedural delays and conjuring political melodrama in hopes of saving himself, Silvio Berlusconi could no longer stave off the inevitable: Italy’s Senate stripped him of his parliamentary seat on Wednesday, a dramatic and humiliating expulsion, even as other potential troubles await him.

In the hours before the vote, Italian senators read speeches for or against Mr. Berlusconi, the powerful former prime minister. Mr. Berlusconi, 77, responded with an outdoor rally in central Rome, transforming the day into a televised, split-screen standoff: On one side was the former prime minister, declaring himself a victim of persecution and pledging to remain a political force; on the other was the Senate, with a majority of rival politicians, who finished their speeches and lowered the boom.

Mr. Berlusconi’s expulsion was confirmed through a series of votes, and after a day of passionate arguments, the reaction in the chamber after the final tally was striking: silence.

“I think we are at a crossroads today,” Senator Pier Ferdinando Casini, who has supported Mr. Berlusconi in the past, said in a speech before the vote. “However it goes, a 20-year period is concluded.”