A filibuster is a Senate practice in which one or more senators prolong debate to delay or prevent a vote on a bill, amendment, or nomination. Because debate in the Senate is generally unlimited, senators may continue debate (or signal intent to do so) to block final consideration unless the Senate votes to end debate.
The filibuster is not mentioned in the Constitution but developed as a result of the Senate’s rules allowing unlimited debate.
What stops a filibuster?
Cloture, the formal Senate procedure to limit debate, ends filibusters.
For most legislation, invoking cloture requires three-fifths of the Senate (normally 60 senators).
For nominations, cloture requires a simple majority (51 senators).
Once cloture is invoked, debate time is limited before a final vote.
Can senators talk about anything in a filibuster?
Generally, yes. Under Senate rules, debate does not have to be strictly limited to the pending question unless the Senate agrees otherwise. This is why historical filibusters sometimes included lengthy or unrelated speeches.
In a traditional “talking filibuster,” a senator must remain standing and speaking continuously. However, in modern practice, a senator does not have to speak continuously to prevent a vote; debate can continue unless cloture is invoked.
Do filibusters always require talking?
There is a Senate practice called a “hold,” which started as an informal practice in the late 1950s, letting senators make routine requests about the Senate’s schedule. Over time, holds evolved into a more powerful tool, sometimes described in the press as a "silent filibuster."
What bills can’t be filibustered?
Certain matters are not subject to filibuster because statute or Senate rules limits debate time.
Some measures considered under expedited statutory procedures, such as budget reconciliation, some trade agreements, and certain war powers resolutions, have statutory limits on debate, which prevent filibusters.
While nominations are subject to debate, cloture on them requires only a simple majority, so they cannot be blocked by a filibuster if a majority supports ending debate.
