A modern filibuster need not consist of uninterrupted speech. The threat of extended debate can be enough to make leaders seek a cloture coalition before committing floor time. The practice changes the effective coalition needed for many measures without changing the simple-majority rule for final passage itself.

The tactic derives from Senate rules and precedents, not Article I. Its scope and procedures can change through Senate action, and exceptions apply in contexts such as reconciliation and nominations.

Identify whether the obstacle is debate or the final vote. Forty-one senators may prevent ordinary cloture even though a majority favors the bill; if cloture is invoked, the Senate still must complete post-cloture consideration and vote on passage.

Video lesson: How a Bill Becomes a Law: Crash Course Government and Politics #9