Filibuster Cask Strength Triple Cask Kentucky Bourbon WhiskeyThe filibuster is a powerful parliamentary procedure in the United States Senate that allows a Senator to speak indefinitely on any subject of his or her choosing in order to prevent a vote on legislation. In order to defeat a filibuster, Senate rules require that at least 60 senators vote to end debate and bring the legislation to a vote. The record for the longest filibuster is held by former Senator Strom Thurmond, who spoke for 24 hours and 18