I think that 60% of the voters have to vote against it. hope that helped! :)
...A Filibuster?
Senators are allowed to speak for or against a bill and a vote can not be taken until the everyone has had a reasonable opportunity to speak. However, there is a tactic known as the filibuster in which a senator or a group of Senators speak for no purpose except to delay a vote on the bill. The Senate can vote to end debate but this action currently required a 60% majority , so unless 60% of the senators want to end debate and get a vote, the debate can go on until the bill is withdrawn without a vote and the bill dies .
The filibuster only exists in the senate. There is no such thing in the House of Representatives. However, in the senate 60 signatures are required to reach cloture on an issue and stop a filibuster
Cloture.
Filibuster http://en.wikipedia.org/wiki/Filibuster
The House of Representatives does not have a filibuster maneuver. The House has a Rules Committee that establishes when a bill will come to the floor and how long debate will be allowed. Filibuster is possible only in the United State Senate, which has no similar set of rules. Because Senate debate is set informally, every Senator has the possibility of speaking. A filibuster can occur when an individual Senator refuses to yield the floor to any other member. A filibuster can be blocked through a complicated process called cloture. Although a series of things have to occur in order to invoke cloture, the bottom line is that 60 Senators must agree to vote for cloture and stop a filibuster. So the short answer is - no filibuster in the House, only in the Senate; and in order to stop filibuster in the Senate, 60 votes are required.
A filibuster.
Members of the legislature can prevent an item from being voted on by speaking without stopping (filibuster), thus refusing to let the item be brought to a vote.
No vote can end a fillibuster. A fillibuster ends only when the person who has the floor sits down, leaves the chamber or cannot continue to speak.
To stall the legislative process a prevent a vote.
Filibuster
3/5ths of senators must vote to end it