The term 'filibuster stopper' refers to the process of cloture, which is a parliamentary procedure used in the United States Senate to end debate on a proposed piece of legislation. Cloture requires the support of three-fifths of the Senate, or 60 senators if there are no vacancies, and is the only way to end a filibuster. It was first introduced in 1917 and has been used hundreds of times since then.