What is the filibuster?

The filibuster is the Senate practice of extending debate to block a vote, and its modern form is simpler and stranger than the movie version: a senator signals objection, and unless 60 of 100 senators vote for cloture to cut off debate, most legislation simply cannot proceed. No one stands, no one reads the phone book; the mere threat suffices, which is why the Senate operates as a 60-vote chamber for most bills.

It appears nowhere in the Constitution. It descends from an 1806 rules cleanup that accidentally deleted the Senate's motion to end debate, a loophole first exploited decades later. The talking filibuster of Mr. Smith Goes to Washington faded after the 1970s, when rule changes let the Senate set blocked bills aside and move on.

Both parties have carved exceptions while in power: budget reconciliation bills, and, since 2013 and 2017, all nominations including the Supreme Court, need only simple majorities. Whether the rest survives is a live argument that conveniently reverses whenever the majority does.