Holding up legislation or other business in the U.S. Senate by organising continuous speeches in opposition so that no vote can be taken. It needs 60 Senators to vote to end a filibuster. Filibusters are often used by minority groups, to offset their numerical disadvantage. In the 111th Congress (2009-11), for example, there were a record number of filibusters in the U.S. Senate, including 100 in the first eleven months, mounted by the Republican minority.